Colors can be specified as hexadecimal triplets, in the form #
, where 
, 
, and 
are the red, green, and blue
components respectively. Thus, for example, #0000ff is fully
saturated blue, #000080 is dark blue, and #ffff00 is
bright yellow (100% red + 100% green).
Alternatively, named colors from the X11R6 color database can be used to specify a color. Note that case is not significant in color names (blue, Blue, BLUE, and bLuE are all acceptable names for the same color). These named colors are available for either X11 or PostScript plots:
AliceBlue green1 orchid AntiqueWhite green2 orchid1 AntiqueWhite1 green3 orchid2 AntiqueWhite2 green4 orchid3 AntiqueWhite3 GreenYellow orchid4 AntiqueWhite4 grey PaleGoldenrod aquamarine honeydew PaleGreen aquamarine1 honeydew1 PaleGreen1 aquamarine2 honeydew2 PaleGreen2 aquamarine3 honeydew3 PaleGreen3 aquamarine4 honeydew4 PaleGreen4 azure HotPink PaleTurquoise azure1 HotPink1 PaleTurquoise1 azure2 HotPink2 PaleTurquoise2 azure3 HotPink3 PaleTurquoise3 azure4 HotPink4 PaleTurquoise4 beige IndianRed PaleVioletRed bisque IndianRed1 PaleVioletRed1 bisque1 IndianRed2 PaleVioletRed2 bisque2 IndianRed3 PaleVioletRed3 bisque3 IndianRed4 PaleVioletRed4 bisque4 ivory PapayaWhip black ivory1 PeachPuff BlanchedAlmond ivory2 PeachPuff1 blue ivory3 PeachPuff2 blue1 ivory4 PeachPuff3 blue2 khaki PeachPuff4 blue3 khaki1 peru blue4 khaki2 pink BlueViolet khaki3 pink1 brown khaki4 pink2 brown1 lavender pink3 brown2 LavenderBlush pink4 brown3 LavenderBlush1 plum brown4 LavenderBlush2 plum1 burlywood LavenderBlush3 plum2 burlywood1 LavenderBlush4 plum3 burlywood2 LawnGreen plum4 burlywood3 LemonChiffon PowderBlue burlywood4 LemonChiffon1 purple CadetBlue LemonChiffon2 purple1 CadetBlue1 LemonChiffon3 purple2 CadetBlue2 LemonChiffon4 purple3 CadetBlue3 LightBlue purple4 CadetBlue4 LightBlue1 red chartreuse LightBlue2 red1 chartreuse1 LightBlue3 red2 chartreuse2 LightBlue4 red3 chartreuse3 LightCoral red4 chartreuse4 LightCyan RosyBrown chocolate LightCyan1 RosyBrown1 chocolate1 LightCyan2 RosyBrown2 chocolate2 LightCyan3 RosyBrown3 chocolate3 LightCyan4 RosyBrown4 chocolate4 LightGoldenrod RoyalBlue coral LightGoldenrod1 RoyalBlue1 coral1 LightGoldenrod2 RoyalBlue2 coral2 LightGoldenrod3 RoyalBlue3 coral3 LightGoldenrod4 RoyalBlue4 coral4 LightGoldenrodYellow SaddleBrown CornflowerBlue LightGray salmon cornsilk LightGreen salmon1 cornsilk1 LightGrey salmon2 cornsilk2 LightPink salmon3 cornsilk3 LightPink1 salmon4 cornsilk4 LightPink2 SandyBrown cyan LightPink3 SeaGreen cyan1 LightPink4 SeaGreen1 cyan2 LightSalmon SeaGreen2 cyan3 LightSalmon1 SeaGreen3 cyan4 LightSalmon2 SeaGreen4 DarkBlue LightSalmon3 seashell DarkCyan LightSalmon4 seashell1 DarkGoldenrod LightSeaGreen seashell2 DarkGoldenrod1 LightSkyBlue seashell3 DarkGoldenrod2 LightSkyBlue1 seashell4 DarkGoldenrod3 LightSkyBlue2 sienna DarkGoldenrod4 LightSkyBlue3 sienna1 DarkGray LightSkyBlue4 sienna2 DarkGreen LightSlateBlue sienna3 DarkGrey LightSlateGray sienna4 DarkKhaki LightSlateGrey SkyBlue DarkMagenta LightSteelBlue SkyBlue1 DarkOliveGreen LightSteelBlue1 SkyBlue2 DarkOliveGreen1 LightSteelBlue2 SkyBlue3 DarkOliveGreen2 LightSteelBlue3 SkyBlue4 DarkOliveGreen3 LightSteelBlue4 SlateBlue DarkOliveGreen4 LightYellow SlateBlue1 DarkOrange LightYellow1 SlateBlue2 DarkOrange1 LightYellow2 SlateBlue3 DarkOrange2 LightYellow3 SlateBlue4 DarkOrange3 LightYellow4 SlateGray DarkOrange4 LimeGreen SlateGray1 DarkOrchid linen SlateGray2 DarkOrchid1 magenta SlateGray3 DarkOrchid2 magenta1 SlateGray4 DarkOrchid3 magenta2 SlateGrey DarkOrchid4 magenta3 snow DarkRed magenta4 snow1 DarkSalmon maroon snow2 DarkSeaGreen maroon1 snow3 DarkSeaGreen1 maroon2 snow4 DarkSeaGreen2 maroon3 SpringGreen DarkSeaGreen3 maroon4 SpringGreen1 DarkSeaGreen4 MediumAquamarine SpringGreen2 DarkSlateBlue MediumBlue SpringGreen3 DarkSlateGray MediumOrchid SpringGreen4 DarkSlateGray1 MediumOrchid1 SteelBlue DarkSlateGray2 MediumOrchid2 SteelBlue1 DarkSlateGray3 MediumOrchid3 SteelBlue2 DarkSlateGray4 MediumOrchid4 SteelBlue3 DarkSlateGrey MediumPurple SteelBlue4 DarkTurquoise MediumPurple1 tan DarkViolet MediumPurple2 tan1 DeepPink MediumPurple3 tan2 DeepPink1 MediumPurple4 tan3 DeepPink2 MediumSeaGreen tan4 DeepPink3 MediumSlateBlue thistle DeepPink4 MediumSpringGreen thistle1 DeepSkyBlue MediumTurquoise thistle2 DeepSkyBlue1 MediumVioletRed thistle3 DeepSkyBlue2 MidnightBlue thistle4 DeepSkyBlue3 MintCream tomato DeepSkyBlue4 MistyRose tomato1 DimGray MistyRose1 tomato2 DimGrey MistyRose2 tomato3 DodgerBlue MistyRose3 tomato4 DodgerBlue1 MistyRose4 turquoise DodgerBlue2 moccasin turquoise1 DodgerBlue3 NavajoWhite turquoise2 DodgerBlue4 NavajoWhite1 turquoise3 firebrick NavajoWhite2 turquoise4 firebrick1 NavajoWhite3 violet firebrick2 NavajoWhite4 VioletRed firebrick3 navy VioletRed1 firebrick4 NavyBlue VioletRed2 FloralWhite OldLace VioletRed3 ForestGreen OliveDrab VioletRed4 gainsboro OliveDrab1 wheat GhostWhite OliveDrab2 wheat1 gold OliveDrab3 wheat2 gold1 OliveDrab4 wheat3 gold2 orange wheat4 gold3 orange1 white gold4 orange2 WhiteSmoke goldenrod orange3 yellow goldenrod1 orange4 yellow1 goldenrod2 OrangeRed yellow2 goldenrod3 OrangeRed1 yellow3 goldenrod4 OrangeRed2 yellow4 gray OrangeRed3 YellowGreen green OrangeRed4
In addition, 101 shades of grey can be specified using grey0 or gray0 (black) through grey100 or gray100 (white).
When producing Postscript plots, plt supplies the translation from color names names to RGB values, so the names above are always available. When producing X11 plots, however, the X server performs the translation; thus, if you are using an old or nonstandard X server, it is possible that a different set of color names may be recognized by the server. If you encounter problems, look for the file rgb.h in the directory that contains `.h' files associated with the X11 libraries; this file will contain the color name database for your X server.