Color
ConTeXt supports two color models: RGB (typically used for screen display) and CMYK (typically used for printing). There is also support for spot colors (typically used for offset printing) and transparencies.
Before you start ...
1. It is usually a bad style to use explicit color switches in the text. It is better to define a semantic command that takes care of the color switching. For example, instead of using \color[red]{important text}
, define
\definehighlight[important][color=red]
and then use \important{important text}
in the text.
2. Colors are not enabled by default in MkII. To enabled colors in MkII, use
\setupcolors[state=start]
3. To disable colors in a document, use
\setupcolors[state=stop]
Basic Usage
To color text, use
\color[defined-color]{ ... text ... }
or
\startcolor[defined-color] ... text ... \stopcolor
where defined-color
is a color defined using \definecolor. For example, red
is one of the predefined colors. So, we can use:
Three \color[red]{cool} cats |
or
\starttext \startcolor[red] \input tufte \stopcolor \stoptext |
It is also possible to use RGB or CMYK or hex values to color text. The syntax for these is
\colored[settings]{... text ...}
where settings
are the same settings as used by \definecolor. For example:
Three \colored[r=0.1, g=0.8, b=0.8]{colorful} cats |
Note. There is no need to use the color commands directly. Almost all ConTeXt commands accept a color
key, and you can use color=defined-color
. For example,
- To color the section titles red, use
\setuphead[color=red]
- To color the footnotes red, use
\setupfootnotes[color=red]
etc.
Pre-defined colors
Default pre-defined colors
The following colors are pre-defined in ConTeXt (see colo-imp-rgb.mkiv).
Name | Color | Name | Color | Name | Color | Name | Color |
---|---|---|---|---|---|---|---|
black | white | ||||||
gray | lightgray | middlegray | darkgray | ||||
red | lightred | middlered | darkred | ||||
green | lightgreen | middlegreen | darkgreen | ||||
blue | lightblue | middleblue | darkblue | ||||
cyan | middlecyan | darkcyan | |||||
magenta | middlemagenta | darkmagenta | |||||
yellow | middleyellow | darkyellow |
X11 Colors
In addition to the above basic color, ConTeXt also includes a definition of the X11 colors. To load this list (colo-imp-xwi.mkiv), use
\usecolors[xwi]
This loads the following additional colors:
Name | Color | Name | Color | Name | Color | Name | Color |
---|---|---|---|---|---|---|---|
aliceblue | antiquewhite | aquamarine | azure | ||||
beige | bisque | black | blanchedalmond | ||||
blue | blueviolet | brown | burlywood | ||||
cadetblue | chartreuse | chocolate | coral | ||||
cornflowerblue | cornsilk | cyan | darkgoldenrod | ||||
darkgreen | darkkhaki | darkolivegreen | darkorange | ||||
darkorchid | darksalmon | darkseagreen | darkslateblue | ||||
darkturquoise | darkviolet | deeppink | deepskyblue | ||||
dodgerblue | firebrick | floralwhite | forestgreen | ||||
gainsboro | ghostwhite | gold | goldenrod | ||||
green | greenyellow | honeydew | hotpink | ||||
indianred | ivory | khaki | lavender | ||||
lavenderblush | lawngreen | lemonchiffon | lightblue | ||||
lightcoral | lightcyan | lightgoldenrod | lightgoldenrodyellow | ||||
lightpink | lightsalmon | lightseagreen | lightskyblue | ||||
lightslateblue | lightsteelblue | lightyellow | limegreen | ||||
linen | magenta | maroon | mediumaquamarine | ||||
mediumblue | mediumorchid | mediumpurple | mediumseagreen | ||||
mediumslateblue | mediumspringgreen | mediumturquoise | mediumvioletred | ||||
midnightblue | mintcream | mistyrose | moccasin | ||||
navajowhite | navy | navyblue | oldlace | ||||
olivedrab | orange | orangered | orchid | ||||
palegoldenrod | palegreen | paleturquoise | palevioletred | ||||
papayawhip | peachpuff | peru | pink | ||||
plum | powderblue | purple | red | ||||
rosybrown | royalblue | saddlebrown | salmon | ||||
sandybrown | seagreen | seashell | sienna | ||||
skyblue | slateblue | snow | springgreen | ||||
steelblue | tan | thistle | tomato | ||||
turquoise | violet | violetred | wheat | ||||
white | whitesmoke | yellow | yellowgreen |
Additional pre-defined colors
In addition to the above, there are two other sets of pre-defined colors.
x11 | \usecolors[x11]
|
colo-imp-x11.mkiv | 658 extended Xorg color keywords (WWW), defined in hex RGB |
crayola | \usecolors[crayola]
|
colo-imp-crayola.mkiv} | 235 Crayola (Binney & Smith) colors |
ema | \usecolors[ema]
|
colo-imp-ema.mkiv | 549 Emacs colors |
RAL | \usecolors[ral]
|
colo-imp-ral.mkiv | 213 RAL color system (Deutsches Institut für Gütesicherung und Kennzeichnung) |
Defining New Colors
New colors may be defined in the following ways
Name | Sytanx (and Example) | Explanation |
---|---|---|
RGB color model | \definecolor[...][r=..., g=..., b=...] For example, \definecolor[lime][r=0.75, g=1, b=0] This is \color[lime]{a new color} that we defined |
The values for r , g , and b are floating point number between 0 and 1 .
|
CMYK color model | \definecolor[...][c=.., m=.., y=.., k=..] For example, \definecolor[lime][c=0.25, m=0, y=1, k=0] This is \color[lime]{a new color} that we defined |
The values for c , m , y and k are floating point number between 0 and 1 .
|
HSV color model | \definecolor[...][h=.., s=.., v=..] For example, \definecolor[lime][h=75, s=1, v=1] This is \color[lime]{a new color} that we defined |
The value for h is between 0 and 360 ; the values for s , v are floating point numbers between 0 and 1 .
|
Hex | \definecolor[...][h=...] For example, \definecolor[lime][h=BFFF00] This is \color[lime]{a new color} that we defined |
The value for x is a three-byte hexadecimal number where the bytes represent the red, green, and blue values. This follows the HTML and CSS style of defining colors.
|
Gray scale | \definecolor[...][s=...] For example, \definecolor[screen][g=0.5] This is \color[screen]{a new color} that we defined |
The value for s is a floating point number between 0 and 1 , representing the grayness value.
|
Note: The key-values are overloaded. For example, h
is used for both HSV model and Hex model; s
is used for both HSV model and grayscale model. The distinction is made based on the presence or absence of the v
key.
Cloning existing colors
You can clone an existing color using
\definecolor[new-color][old-color]
For example
\usecolors[xwi] \definecolor[highlight][yellow] \defineframed [important] [location=low, frame=off, background=color, backgroundcolor=highlight] This is a \important{important}word. \definecolor[highlight][lavenderblush] This is a \important{important}word. |
Adapting existing colors
|
TODO: add details about this (See: To-Do List) |
Advanced Usage
Changing color of entire document
To change the main text color of the document use
\setupcolors[textcolor=defined-color]
For example,
\setupcolors[textcolor=blue] \starttext text \stoptext |
Changing background color of page
The background color of the page can be changed using
\setupbackgrounds[page][background=color,backgroundcolor=defined-color]
For example,
\setuppapersize[A10] \setupbackgrounds[page][background=color,backgroundcolor=blue] \starttext text \stoptext |
Using colors in MetaPost
A color defined in TeX is available in MetaPost using \MPcolor{...}
. For example:
\definecolor[highlight][r=0.8,g=0.8,b=0] \starttext \color[highlight]{Highlighted text in TeX} \startMPcode label("Highlighted text in MetaPost", origin) withcolor \MPcolor{highlight}; \stopMPcode |
Note that \MPcolor{...}
behaves similar to a color
primitive in MetaPost. For example, the following is valid MetaPost code.
color myColor; myColor = 0.5[\MPcolor{highlight}, white];
Using colors in TikZ
Viewing pre-defined color
View all defined colors
To view pre-defined colors, you can use \showcolor. For example, to see all the colors defined in colo-imp-x11.mkiv, use (output truncated for display here ...)
\showcolor[x11] |
If you use \showcolor without any argument, all currently defined colors are shown.
View specific defined colors
To view the components of a defined color, you can use:
\showcolorcomponents[color-1, color-2]
For example,
\showcolorcomponents[red,middlered,darkred] |
\colorcompoents{defined-color} \tranparencycomponents{defined-color} \processcolorcomponents{defined-color}
For example,
\startlines \colorcomponents{red} \transparencycomponents{red} \processcolorcomponents{red} \stoplines |
|
Testing if color is defined
To test if a color is defined, use
Usage:
\doifcolor{color-name}{... if branch ... } \doifcolorelse{color-name}{... if branch ...}{... else branch ...}
Specialized topics
References
- Paletton - Website to choose color palettes
- ColorBrewer - website to choose colors for maps and graphics.
- Tina Sutton, Bride M Whelan: The Complete Color Harmony. Rockport Publishers (2004). ISBN 978-1592530311 (recommanded in the mailing list)