;;; color.scm -- Color management.
;;;
;;; Copyright 2003, 2004  Erick Gallesio - I3S-CNRS/ESSI <eg@essi.fr>
;;; Copyright 2006  Ludovic Courtès  <ludovic.courtes@laas.fr>
;;;
;;;
;;; This program is free software; you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 2 of the License, or
;;; (at your option) any later version.
;;;
;;; This program is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program; if not, write to the Free Software
;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
;;; USA.


(define-module (skribilo color)
  :autoload (srfi srfi-60) (bitwise-and arithmetic-shift)
  :export (skribe-color->rgb skribe-get-used-colors skribe-use-color!))

;; FIXME: This module should be generalized and the `skribe-' procedures
;; moved to `compat.scm'.

;; FIXME: Use a fluid?  Or remove it?
(define *used-colors* '())

(define *skribe-rgb-alist* '(
   ("snow"			. "255 250 250")
   ("ghostwhite"		. "248 248 255")
   ("whitesmoke"		. "245 245 245")
   ("gainsboro"			. "220 220 220")
   ("floralwhite"		. "255 250 240")
   ("oldlace"			. "253 245 230")
   ("linen"			. "250 240 230")
   ("antiquewhite"		. "250 235 215")
   ("papayawhip"		. "255 239 213")
   ("blanchedalmond"		. "255 235 205")
   ("bisque"			. "255 228 196")
   ("peachpuff"			. "255 218 185")
   ("navajowhite"		. "255 222 173")
   ("moccasin"			. "255 228 181")
   ("cornsilk"			. "255 248 220")
   ("ivory"			. "255 255 240")
   ("lemonchiffon"		. "255 250 205")
   ("seashell"			. "255 245 238")
   ("honeydew"			. "240 255 240")
   ("mintcream"			. "245 255 250")
   ("azure"			. "240 255 255")
   ("aliceblue"			. "240 248 255")
   ("lavender"			. "230 230 250")
   ("lavenderblush"		. "255 240 245")
   ("mistyrose"			. "255 228 225")
   ("white"			. "255 255 255")
   ("black"			. "0 0 0")
   ("darkslategrey"		. "47 79 79")
   ("dimgrey"			. "105 105 105")
   ("slategrey"			. "112 128 144")
   ("lightslategrey"		. "119 136 153")
   ("grey"			. "190 190 190")
   ("lightgrey"			. "211 211 211")
   ("midnightblue"		. "25 25 112")
   ("navy"			. "0 0 128")
   ("navyblue"			. "0 0 128")
   ("cornflowerblue"		. "100 149 237")
   ("darkslateblue"		. "72 61 139")
   ("slateblue"			. "106 90 205")
   ("mediumslateblue"		. "123 104 238")
   ("lightslateblue"		. "132 112 255")
   ("mediumblue"		. "0 0 205")
   ("royalblue"			. "65 105 225")
   ("blue"			. "0 0 255")
   ("dodgerblue"		. "30 144 255")
   ("deepskyblue"		. "0 191 255")
   ("skyblue"			. "135 206 235")
   ("lightskyblue"		. "135 206 250")
   ("steelblue"			. "70 130 180")
   ("lightsteelblue"		. "176 196 222")
   ("lightblue"			. "173 216 230")
   ("powderblue"		. "176 224 230")
   ("paleturquoise"		. "175 238 238")
   ("darkturquoise"		. "0 206 209")
   ("mediumturquoise"		. "72 209 204")
   ("turquoise"			. "64 224 208")
   ("cyan"			. "0 255 255")
   ("lightcyan"			. "224 255 255")
   ("cadetblue"			. "95 158 160")
   ("mediumaquamarine"		. "102 205 170")
   ("aquamarine"		. "127 255 212")
   ("darkgreen"			. "0 100 0")
   ("darkolivegreen"		. "85 107 47")
   ("darkseagreen"		. "143 188 143")
   ("seagreen"			. "46 139 87")
   ("mediumseagreen"		. "60 179 113")
   ("lightseagreen"		. "32 178 170")
   ("palegreen"			. "152 251 152")
   ("springgreen"		. "0 255 127")
   ("lawngreen"			. "124 252 0")
   ("green"			. "0 255 0")
   ("chartreuse"		. "127 255 0")
   ("mediumspringgreen"		. "0 250 154")
   ("greenyellow"		. "173 255 47")
   ("limegreen"			. "50 205 50")
   ("yellowgreen"		. "154 205 50")
   ("forestgreen"		. "34 139 34")
   ("olivedrab"			. "107 142 35")
   ("darkkhaki"			. "189 183 107")
   ("khaki"			. "240 230 140")
   ("palegoldenrod"		. "238 232 170")
   ("lightgoldenrodyellow"	. "250 250 210")
   ("lightyellow"		. "255 255 224")
   ("yellow"			. "255 255 0")
   ("gold"			. "255 215 0")
   ("lightgoldenrod"		. "238 221 130")
   ("goldenrod"			. "218 165 32")
   ("darkgoldenrod"		. "184 134 11")
   ("rosybrown"			. "188 143 143")
   ("indianred"			. "205 92 92")
   ("saddlebrown"		. "139 69 19")
   ("sienna"			. "160 82 45")
   ("peru"			. "205 133 63")
   ("burlywood"			. "222 184 135")
   ("beige"			. "245 245 220")
   ("wheat"			. "245 222 179")
   ("sandybrown"		. "244 164 96")
   ("tan"			. "210 180 140")
   ("chocolate"			. "210 105 30")
   ("firebrick"			. "178 34 34")
   ("brown"			. "165 42 42")
   ("darksalmon"		. "233 150 122")
   ("salmon"			. "250 128 114")
   ("lightsalmon"		. "255 160 122")
   ("orange"			. "255 165 0")
   ("darkorange"		. "255 140 0")
   ("coral"			. "255 127 80")
   ("lightcoral"		. "240 128 128")
   ("tomato"			. "255 99 71")
   ("orangered"			. "255 69 0")
   ("red"			. "255 0 0")
   ("hotpink"			. "255 105 180")
   ("deeppink"			. "255 20 147")
   ("pink"			. "255 192 203")
   ("lightpink"			. "255 182 193")
   ("palevioletred"		. "219 112 147")
   ("maroon"			. "176 48 96")
   ("mediumvioletred"		. "199 21 133")
   ("violetred"			. "208 32 144")
   ("magenta"			. "255 0 255")
   ("violet"			. "238 130 238")
   ("plum"			. "221 160 221")
   ("orchid"			. "218 112 214")
   ("mediumorchid"		. "186 85 211")
   ("darkorchid"		. "153 50 204")
   ("darkviolet"		. "148 0 211")
   ("blueviolet"		. "138 43 226")
   ("purple"			. "160 32 240")
   ("mediumpurple"		. "147 112 219")
   ("thistle"			. "216 191 216")
   ("snow1"			. "255 250 250")
   ("snow2"			. "238 233 233")
   ("snow3"			. "205 201 201")
   ("snow4"			. "139 137 137")
   ("seashell1"			. "255 245 238")
   ("seashell2"			. "238 229 222")
   ("seashell3"			. "205 197 191")
   ("seashell4"			. "139 134 130")
   ("antiquewhite1"		. "255 239 219")
   ("antiquewhite2"		. "238 223 204")
   ("antiquewhite3"		. "205 192 176")
   ("antiquewhite4"		. "139 131 120")
   ("bisque1"			. "255 228 196")
   ("bisque2"			. "238 213 183")
   ("bisque3"			. "205 183 158")
   ("bisque4"			. "139 125 107")
   ("peachpuff1"		. "255 218 185")
   ("peachpuff2"		. "238 203 173")
   ("peachpuff3"		. "205 175 149")
   ("peachpuff4"		. "139 119 101")
   ("navajowhite1"		. "255 222 173")
   ("navajowhite2"		. "238 207 161")
   ("navajowhite3"		. "205 179 139")
   ("navajowhite4"		. "139 121 94")
   ("lemonchiffon1"		. "255 250 205")
   ("lemonchiffon2"		. "238 233 191")
   ("lemonchiffon3"		. "205 201 165")
   ("lemonchiffon4"		. "139 137 112")
   ("cornsilk1"			. "255 248 220")
   ("cornsilk2"			. "238 232 205")
   ("cornsilk3"			. "205 200 177")
   ("cornsilk4"			. "139 136 120")
   ("ivory1"			. "255 255 240")
   ("ivory2"			. "238 238 224")
   ("ivory3"			. "205 205 193")
   ("ivory4"			. "139 139 131")
   ("honeydew1"			. "240 255 240")
   ("honeydew2"			. "224 238 224")
   ("honeydew3"			. "193 205 193")
   ("honeydew4"			. "131 139 131")
   ("lavenderblush1"		. "255 240 245")
   ("lavenderblush2"		. "238 224 229")
   ("lavenderblush3"		. "205 193 197")
   ("lavenderblush4"		. "139 131 134")
   ("mistyrose1"		. "255 228 225")
   ("mistyrose2"		. "238 213 210")
   ("mistyrose3"		. "205 183 181")
   ("mistyrose4"		. "139 125 123")
   ("azure1"			. "240 255 255")
   ("azure2"			. "224 238 238")
   ("azure3"			. "193 205 205")
   ("azure4"			. "131 139 139")
   ("slateblue1"		. "131 111 255")
   ("slateblue2"		. "122 103 238")
   ("slateblue3"		. "105 89 205")
   ("slateblue4"		. "71 60 139")
   ("royalblue1"		. "72 118 255")
   ("royalblue2"		. "67 110 238")
   ("royalblue3"		. "58 95 205")
   ("royalblue4"		. "39 64 139")
   ("blue1"			. "0 0 255")
   ("blue2"			. "0 0 238")
   ("blue3"			. "0 0 205")
   ("blue4"			. "0 0 139")
   ("dodgerblue1"		. "30 144 255")
   ("dodgerblue2"		. "28 134 238")
   ("dodgerblue3"		. "24 116 205")
   ("dodgerblue4"		. "16 78 139")
   ("steelblue1"		. "99 184 255")
   ("steelblue2"		. "92 172 238")
   ("steelblue3"		. "79 148 205")
   ("steelblue4"		. "54 100 139")
   ("deepskyblue1"		. "0 191 255")
   ("deepskyblue2"		. "0 178 238")
   ("deepskyblue3"		. "0 154 205")
   ("deepskyblue4"		. "0 104 139")
   ("skyblue1"			. "135 206 255")
   ("skyblue2"			. "126 192 238")
   ("skyblue3"			. "108 166 205")
   ("skyblue4"			. "74 112 139")
   ("lightskyblue1"		. "176 226 255")
   ("lightskyblue2"		. "164 211 238")
   ("lightskyblue3"		. "141 182 205")
   ("lightskyblue4"		. "96 123 139")
   ("lightsteelblue1"		. "202 225 255")
   ("lightsteelblue2"		. "188 210 238")
   ("lightsteelblue3"		. "162 181 205")
   ("lightsteelblue4"		. "110 123 139")
   ("lightblue1"		. "191 239 255")
   ("lightblue2"		. "178 223 238")
   ("lightblue3"		. "154 192 205")
   ("lightblue4"		. "104 131 139")
   ("lightcyan1"		. "224 255 255")
   ("lightcyan2"		. "209 238 238")
   ("lightcyan3"		. "180 205 205")
   ("lightcyan4"		. "122 139 139")
   ("paleturquoise1"		. "187 255 255")
   ("paleturquoise2"		. "174 238 238")
   ("paleturquoise3"		. "150 205 205")
   ("paleturquoise4"		. "102 139 139")
   ("cadetblue1"		. "152 245 255")
   ("cadetblue2"		. "142 229 238")
   ("cadetblue3"		. "122 197 205")
   ("cadetblue4"		. "83 134 139")
   ("turquoise1"		. "0 245 255")
   ("turquoise2"		. "0 229 238")
   ("turquoise3"		. "0 197 205")
   ("turquoise4"		. "0 134 139")
   ("cyan1"			. "0 255 255")
   ("cyan2"			. "0 238 238")
   ("cyan3"			. "0 205 205")
   ("cyan4"			. "0 139 139")
   ("aquamarine1"		. "127 255 212")
   ("aquamarine2"		. "118 238 198")
   ("aquamarine3"		. "102 205 170")
   ("aquamarine4"		. "69 139 116")
   ("darkseagreen1"		. "193 255 193")
   ("darkseagreen2"		. "180 238 180")
   ("darkseagreen3"		. "155 205 155")
   ("darkseagreen4"		. "105 139 105")
   ("seagreen1"			. "84 255 159")
   ("seagreen2"			. "78 238 148")
   ("seagreen3"			. "67 205 128")
   ("seagreen4"			. "46 139 87")
   ("palegreen1"		. "154 255 154")
   ("palegreen2"		. "144 238 144")
   ("palegreen3"		. "124 205 124")
   ("palegreen4"		. "84 139 84")
   ("springgreen1"		. "0 255 127")
   ("springgreen2"		. "0 238 118")
   ("springgreen3"		. "0 205 102")
   ("springgreen4"		. "0 139 69")
   ("green1"			. "0 255 0")
   ("green2"			. "0 238 0")
   ("green3"			. "0 205 0")
   ("green4"			. "0 139 0")
   ("chartreuse1"		. "127 255 0")
   ("chartreuse2"		. "118 238 0")
   ("chartreuse3"		. "102 205 0")
   ("chartreuse4"		. "69 139 0")
   ("olivedrab1"		. "192 255 62")
   ("olivedrab2"		. "179 238 58")
   ("olivedrab3"		. "154 205 50")
   ("olivedrab4"		. "105 139 34")
   ("darkolivegreen1"		. "202 255 112")
   ("darkolivegreen2"		. "188 238 104")
   ("darkolivegreen3"		. "162 205 90")
   ("darkolivegreen4"		. "110 139 61")
   ("khaki1"			. "255 246 143")
   ("khaki2"			. "238 230 133")
   ("khaki3"			. "205 198 115")
   ("khaki4"			. "139 134 78")
   ("lightgoldenrod1"		. "255 236 139")
   ("lightgoldenrod2"		. "238 220 130")
   ("lightgoldenrod3"		. "205 190 112")
   ("lightgoldenrod4"		. "139 129 76")
   ("lightyellow1"		. "255 255 224")
   ("lightyellow2"		. "238 238 209")
   ("lightyellow3"		. "205 205 180")
   ("lightyellow4"		. "139 139 122")
   ("yellow1"			. "255 255 0")
   ("yellow2"			. "238 238 0")
   ("yellow3"			. "205 205 0")
   ("yellow4"			. "139 139 0")
   ("gold1"			. "255 215 0")
   ("gold2"			. "238 201 0")
   ("gold3"			. "205 173 0")
   ("gold4"			. "139 117 0")
   ("goldenrod1"		. "255 193 37")
   ("goldenrod2"		. "238 180 34")
   ("goldenrod3"		. "205 155 29")
   ("goldenrod4"		. "139 105 20")
   ("darkgoldenrod1"		. "255 185 15")
   ("darkgoldenrod2"		. "238 173 14")
   ("darkgoldenrod3"		. "205 149 12")
   ("darkgoldenrod4"		. "139 101 8")
   ("rosybrown1"		. "255 193 193")
   ("rosybrown2"		. "238 180 180")
   ("rosybrown3"		. "205 155 155")
   ("rosybrown4"		. "139 105 105")
   ("indianred1"		. "255 106 106")
   ("indianred2"		. "238 99 99")
   ("indianred3"		. "205 85 85")
   ("indianred4"		. "139 58 58")
   ("sienna1"			. "255 130 71")
   ("sienna2"			. "238 121 66")
   ("sienna3"			. "205 104 57")
   ("sienna4"			. "139 71 38")
   ("burlywood1"		. "255 211 155")
   ("burlywood2"		. "238 197 145")
   ("burlywood3"		. "205 170 125")
   ("burlywood4"		. "139 115 85")
   ("wheat1"			. "255 231 186")
   ("wheat2"			. "238 216 174")
   ("wheat3"			. "205 186 150")
   ("wheat4"			. "139 126 102")
   ("tan1"			. "255 165 79")
   ("tan2"			. "238 154 73")
   ("tan3"			. "205 133 63")
   ("tan4"			. "139 90 43")
   ("chocolate1"		. "255 127 36")
   ("chocolate2"		. "238 118 33")
   ("chocolate3"		. "205 102 29")
   ("chocolate4"		. "139 69 19")
   ("firebrick1"		. "255 48 48")
   ("firebrick2"		. "238 44 44")
   ("firebrick3"		. "205 38 38")
   ("firebrick4"		. "139 26 26")
   ("brown1"			. "255 64 64")
   ("brown2"			. "238 59 59")
   ("brown3"			. "205 51 51")
   ("brown4"			. "139 35 35")
   ("salmon1"			. "255 140 105")
   ("salmon2"			. "238 130 98")
   ("salmon3"			. "205 112 84")
   ("salmon4"			. "139 76 57")
   ("lightsalmon1"		. "255 160 122")
   ("lightsalmon2"		. "238 149 114")
   ("lightsalmon3"		. "205 129 98")
   ("lightsalmon4"		. "139 87 66")
   ("orange1"			. "255 165 0")
   ("orange2"			. "238 154 0")
   ("orange3"			. "205 133 0")
   ("orange4"			. "139 90 0")
   ("darkorange1"		. "255 127 0")
   ("darkorange2"		. "238 118 0")
   ("darkorange3"		. "205 102 0")
   ("darkorange4"		. "139 69 0")
   ("coral1"			. "255 114 86")
   ("coral2"			. "238 106 80")
   ("coral3"			. "205 91 69")
   ("coral4"			. "139 62 47")
   ("tomato1"			. "255 99 71")
   ("tomato2"			. "238 92 66")
   ("tomato3"			. "205 79 57")
   ("tomato4"			. "139 54 38")
   ("orangered1"		. "255 69 0")
   ("orangered2"		. "238 64 0")
   ("orangered3"		. "205 55 0")
   ("orangered4"		. "139 37 0")
   ("red1"			. "255 0 0")
   ("red2"			. "238 0 0")
   ("red3"			. "205 0 0")
   ("red4"			. "139 0 0")
   ("deeppink1"			. "255 20 147")
   ("deeppink2"			. "238 18 137")
   ("deeppink3"			. "205 16 118")
   ("deeppink4"			. "139 10 80")
   ("hotpink1"			. "255 110 180")
   ("hotpink2"			. "238 106 167")
   ("hotpink3"			. "205 96 144")
   ("hotpink4"			. "139 58 98")
   ("pink1"			. "255 181 197")
   ("pink2"			. "238 169 184")
   ("pink3"			. "205 145 158")
   ("pink4"			. "139 99 108")
   ("lightpink1"		. "255 174 185")
   ("lightpink2"		. "238 162 173")
   ("lightpink3"		. "205 140 149")
   ("lightpink4"		. "139 95 101")
   ("palevioletred1"		. "255 130 171")
   ("palevioletred2"		. "238 121 159")
   ("palevioletred3"		. "205 104 137")
   ("palevioletred4"		. "139 71 93")
   ("maroon1"			. "255 52 179")
   ("maroon2"			. "238 48 167")
   ("maroon3"			. "205 41 144")
   ("maroon4"			. "139 28 98")
   ("violetred1"		. "255 62 150")
   ("violetred2"		. "238 58 140")
   ("violetred3"		. "205 50 120")
   ("violetred4"		. "139 34 82")
   ("magenta1"			. "255 0 255")
   ("magenta2"			. "238 0 238")
   ("magenta3"			. "205 0 205")
   ("magenta4"			. "139 0 139")
   ("orchid1"			. "255 131 250")
   ("orchid2"			. "238 122 233")
   ("orchid3"			. "205 105 201")
   ("orchid4"			. "139 71 137")
   ("plum1"			. "255 187 255")
   ("plum2"			. "238 174 238")
   ("plum3"			. "205 150 205")
   ("plum4"			. "139 102 139")
   ("mediumorchid1"		. "224 102 255")
   ("mediumorchid2"		. "209 95 238")
   ("mediumorchid3"		. "180 82 205")
   ("mediumorchid4"		. "122 55 139")
   ("darkorchid1"		. "191 62 255")
   ("darkorchid2"		. "178 58 238")
   ("darkorchid3"		. "154 50 205")
   ("darkorchid4"		. "104 34 139")
   ("purple1"			. "155 48 255")
   ("purple2"			. "145 44 238")
   ("purple3"			. "125 38 205")
   ("purple4"			. "85 26 139")
   ("mediumpurple1"		. "171 130 255")
   ("mediumpurple2"		. "159 121 238")
   ("mediumpurple3"		. "137 104 205")
   ("mediumpurple4"		. "93 71 139")
   ("thistle1"			. "255 225 255")
   ("thistle2"			. "238 210 238")
   ("thistle3"			. "205 181 205")
   ("thistle4"			. "139 123 139")
   ("grey0"			. "0 0 0")
   ("grey1"			. "3 3 3")
   ("grey2"			. "5 5 5")
   ("grey3"			. "8 8 8")
   ("grey4"			. "10 10 10")
   ("grey5"			. "13 13 13")
   ("grey6"			. "15 15 15")
   ("grey7"			. "18 18 18")
   ("grey8"			. "20 20 20")
   ("grey9"			. "23 23 23")
   ("grey10"			. "26 26 26")
   ("grey11"			. "28 28 28")
   ("grey12"			. "31 31 31")
   ("grey13"			. "33 33 33")
   ("grey14"			. "36 36 36")
   ("grey15"			. "38 38 38")
   ("grey16"			. "41 41 41")
   ("grey17"			. "43 43 43")
   ("grey18"			. "46 46 46")
   ("grey19"			. "48 48 48")
   ("grey20"			. "51 51 51")
   ("grey21"			. "54 54 54")
   ("grey22"			. "56 56 56")
   ("grey23"			. "59 59 59")
   ("grey24"			. "61 61 61")
   ("grey25"			. "64 64 64")
   ("grey26"			. "66 66 66")
   ("grey27"			. "69 69 69")
   ("grey28"			. "71 71 71")
   ("grey29"			. "74 74 74")
   ("grey30"			. "77 77 77")
   ("grey31"			. "79 79 79")
   ("grey32"			. "82 82 82")
   ("grey33"			. "84 84 84")
   ("grey34"			. "87 87 87")
   ("grey35"			. "89 89 89")
   ("grey36"			. "92 92 92")
   ("grey37"			. "94 94 94")
   ("grey38"			. "97 97 97")
   ("grey39"			. "99 99 99")
   ("grey40"			. "102 102 102")
   ("grey41"			. "105 105 105")
   ("grey42"			. "107 107 107")
   ("grey43"			. "110 110 110")
   ("grey44"			. "112 112 112")
   ("grey45"			. "115 115 115")
   ("grey46"			. "117 117 117")
   ("grey47"			. "120 120 120")
   ("grey48"			. "122 122 122")
   ("grey49"			. "125 125 125")
   ("grey50"			. "127 127 127")
   ("grey51"			. "130 130 130")
   ("grey52"			. "133 133 133")
   ("grey53"			. "135 135 135")
   ("grey54"			. "138 138 138")
   ("grey55"			. "140 140 140")
   ("grey56"			. "143 143 143")
   ("grey57"			. "145 145 145")
   ("grey58"			. "148 148 148")
   ("grey59"			. "150 150 150")
   ("grey60"			. "153 153 153")
   ("grey61"			. "156 156 156")
   ("grey62"			. "158 158 158")
   ("grey63"			. "161 161 161")
   ("grey64"			. "163 163 163")
   ("grey65"			. "166 166 166")
   ("grey66"			. "168 168 168")
   ("grey67"			. "171 171 171")
   ("grey68"			. "173 173 173")
   ("grey69"			. "176 176 176")
   ("grey70"			. "179 179 179")
   ("grey71"			. "181 181 181")
   ("grey72"			. "184 184 184")
   ("grey73"			. "186 186 186")
   ("grey74"			. "189 189 189")
   ("grey75"			. "191 191 191")
   ("grey76"			. "194 194 194")
   ("grey77"			. "196 196 196")
   ("grey78"			. "199 199 199")
   ("grey79"			. "201 201 201")
   ("grey80"			. "204 204 204")
   ("grey81"			. "207 207 207")
   ("grey82"			. "209 209 209")
   ("grey83"			. "212 212 212")
   ("grey84"			. "214 214 214")
   ("grey85"			. "217 217 217")
   ("grey86"			. "219 219 219")
   ("grey87"			. "222 222 222")
   ("grey88"			. "224 224 224")
   ("grey89"			. "227 227 227")
   ("grey90"			. "229 229 229")
   ("grey91"			. "232 232 232")
   ("grey92"			. "235 235 235")
   ("grey93"			. "237 237 237")
   ("grey94"			. "240 240 240")
   ("grey95"			. "242 242 242")
   ("grey96"			. "245 245 245")
   ("grey97"			. "247 247 247")
   ("grey98"			. "250 250 250")
   ("grey99"			. "252 252 252")
   ("grey100"			. "255 255 255")
   ("darkgrey"			. "169 169 169")
   ("darkblue"			. "0 0 139")
   ("darkcyan"			. "0 139 139")
   ("darkmagenta"		. "139 0 139")
   ("darkred"			. "139 0 0")
   ("lightgreen"		. "144 238 144")
   ("lightred"			. "255 127 127")))


(define (%convert-color str)
  (let ((col (assoc str *skribe-rgb-alist*)))
    (cond
      (col
       (let* ((p (open-input-string (cdr col)))
	      (r (read p))
	      (g (read p))
	      (b (read p)))
	 (values r g b)))
      ((and (string? str) (eq? (string-ref str 0) #\#) (= (string-length str) 7))
       (values (string->number (substring str 1 3) 16)
	       (string->number (substring str 3 5) 16)
	       (string->number (substring str 5 7) 16)))
      ((and (string? str) (eq? (string-ref str 0) #\#) (= (string-length str) 13))
       (values (string->number (substring str 1 5) 16)
	       (string->number (substring str 5 9) 16)
	       (string->number (substring str 9 13) 16)))
      (else
       (values 0 0 0)))))

;;;
;;; SKRIBE-COLOR->RGB
;;;
(define (skribe-color->rgb spec)
  (cond
    ((string? spec) (%convert-color spec))
    ((integer? spec)
       (values (bitwise-and #xff (arithmetic-shift spec -16))
	       (bitwise-and #xff (arithmetic-shift spec -8))
	       (bitwise-and #xff spec)))
    (else
     (values 0 0 0))))

;;;
;;; SKRIBE-GET-USED-COLORS
;;;
(define (skribe-get-used-colors)
   *used-colors*)

;;;
;;; SKRIBE-USE-COLOR!
;;;
(define (skribe-use-color! color)
  (set! *used-colors* (cons color *used-colors*))
  color)