List of software palettes

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This is a list of software palettes used by computers. Systems that use a 4-bit or 8-bit pixel depth can display up to 16 or 256 colors simultaneously. Many personal computers in the early 1990 displayed at most 256 different colors, freely selected by software (either by the user or by a program) from their wider hardware's RGB color palette.

Contents

Usual selections of colors in limited subsets (generally 16 or 256) of the full palette includes some RGB level arrangements commonly used with the 8-bit palettes as master palettes or universal palettes (i.e., palettes for multipurpose uses).

These are some representative software palettes, but any selection can be made in such of systems.

For specific hardware color palettes, see the List of monochrome and RGB palettes, List of 8-bit computer hardware palettes, the List of 16-bit computer hardware palettes and the List of videogame consoles palettes articles.

Each palette is represented by an array of color patches. A one-pixel size version appears below each palette, to make it easy to compare palette sizes.

For each unique palette, an image color test chart and sample image (truecolor original follows) rendered with that palette (without dithering) are given. The test chart shows the full 8-bit, 256 levels of the red, green, and blue (RGB) primary colors and cyan, magenta, and yellow complementary colors, along with a full 8-bit, 256 levels grayscale. Gradients of RGB intermediate colors (orange, lime green, sea green, sky blue, violet and fuchsia), and a full hue spectrum are also present. Color charts are not gamma corrected.

RGB 24bits palette sample image.jpg RGB 24bits palette color test chart.png

These elements illustrate the color depth and distribution of the colors of any given palette, and the sample image indicates how the color selection of such palettes could represent real-life images.

System specifics

These are selections of colors officially employed as system palettes in some popular operating systems for personal computers that support 8-bit displays.

Microsoft Windows default 16-color palette

Windows 16colors palette sample image.png Windows 16colors palette color test chart.png

Used by this platform as a roughly backward compatible palette for the CGA, EGA and VGA text modes, but with colors arranged in a different order. Also is the default palette for 16 color icons.

Windows 16colors palette.png

The corresponding indices into this palette are:

0 — black8 — gray
1 — maroon9 — red
2 — green10 — lime
3 — olive11 — yellow
4 — navy12 — blue
5 — purple13 — fuchsia
6 — teal14 — aqua
7 — silver15 — white

Microsoft Windows default 20-color palette

Windows 20colors palette sample image.png Windows 20colors palette color test chart.png

In 256-color mode, there are four additional standard Windows colors, twenty system reserved colors in total; [1] [2] thus the system leaves 236 palette indexes free for applications to use. The system color entries inside a 256-color palette table are the first ten plus the last ten. In any case, the additional system colors do not seem to add a sharp color richness: they are only some intermediate shades of grayish colors.

Windows 20colors palette.png

The complete 20-color Windows' system palette is:

0 — black246 — cream
1 — dark red247 — medium grey
2 — dark green248 — dark grey
3 — dark yellow249 — red
4 — dark blue250 — green
5 — dark magenta251 — yellow
6 — dark cyan252 — blue
7 — light grey253 — magenta
8 — money green254 — cyan
9 — sky blue255 — white

Apple Macintosh default 16-color palette

Mac 16colors palette sample image.png Mac 16colors palette color test chart.png

When Apple Computer introduced the Macintosh II in 1987, this 16-color palette was included in System 4.1.

Mac 16colors palette.png
0 — white8 — green
1 — yellow9 — dark green
2 — orange10 — brown
3 — red11 — tan
4 — magenta12 — light grey
5 — purple13 — medium grey
6 — blue14 — dark grey
7 — cyan15 — black

RISC OS default palette

RiscOS 16colors palette sample image.png RiscOS 16colors palette color test chart.png

Acorn RISC OS 2.x and 3.x provided this 16-color palette: [3]

RiscOS 16colors palette.png
0 — white8 — dark blue
1 — grey #19 — yellow
2 — grey #210 — green
3 — grey #311 — red
4 — grey #412 — beige
5 — grey #513 — dark green
6 — grey #614 — orange
7 — black15 — light blue

RGB arrangements

These are selections of colors based in evenly ordered RGB levels which provide complete RGB combinations, mainly used as master palettes to display any kind of image within the limitations of the 8-bit pixel depth.

6 level RGB

RGB 6levels palette sample image.png RGB 6levels palette color test chart.png
Red#000000#330000#660000#990000#CC0000#FF0000
Green#000000#003300#006600#009900#00CC00#00FF00
Blue#000000#000033#000066#000099#0000CC#0000FF

Having six levels for every primary, with 6³ = 216 combinations. The index can be addressed by (36×R)+(6×G)+B, with all R, G and B values in a range from 0 to 5. Intended as homogeneous RGB cube, it gives six true grays. Also, there is room for another sorts of 40 colors, so operating systems or programs can add extra colors.

RGB 6levels palette.png

Systems that use this software palette are:

6-7-6 levels RGB

RGB 6-7-6-levels palette sample image.png RGB 6-7-6-levels palette color test chart.png
Red#000000#330000#660000#990000#CC0000#FF0000
Green#000000#002A00#005500#008000#00AA00#00D400#00FF00
Blue#000000#000033#000066#000099#0000CC#0000FF

This palette is constructed with six levels for red and blue primaries and seven levels for the green primary, giving 6×7×6 = 252 combinations. The index can be addressed by (42×R)+(6×G)+B, with R and B values in a range from 0 to 5 and G in a range from 0 to 6. The same case as the former, but with an added level of green due to the greater sensibility of the normal human eye to this frequency.

RGB 6-7-6levels palette.png

It does not provide true grays, but remaining indexes can be filled with four intermediate grays. In any case, there is little room for any other color.

6-8-5 levels RGB

RGB 6-8-5levels palette sample image.png RGB 6-8-5levels palette color test chart.png
Red#000000#330000#660000#990000#CC0000#FF0000
Green#000000#002400#004900#006D00#009200#00B600#00DB00#00FF00
Blue#000000#000040#000080#0000BF#0000FF

This palette is constructed with six levels for red, eight levels for green and five levels for the blue primaries, giving 6×8×5 = 240 combinations. The index can be addressed by (40×R)+(5×G)+B, with R ranging from 0 to 5, G from 0 to 7 and B from 0 to 4. Levels are chosen in function of sensibility of the normal human eye to every primary color.

RGB 6-8-5levels palette.png

Also, it does not provide true grays. Remaining indexes can be filled with sixteen intermediate grays or other fixed colors. In fact, this is the best balanced RGB master software palette[ citation needed ], in a compromise between the RGB arrangement based in the human eye's sensibility and a sufficient remaining palette entries for another purposes.

8-8-4 levels RGB

RGB 8-8-4-levels palette sample image.png RGB 8-8-4-levels palette color test chart.png
Red#000000#240000#490000#6D0000#920000#B60000#DB0000#FF0000
Green#000000#002400#004900#006D00#009200#00B600#00DB00#00FF00
Blue#000000#000055#0000AA#0000FF

The 8-8-4 level RGB use eight levels for each of the red and green color components (3+3 high order bits), and four levels (2 low order bits) for the blue component, due to the lesser sensitivity of the normal human eye to this primary color. This results in an 8×8×4 = 256-color palette as follows:

RGB 8-8-4-levels palette.png

This RGB software palette occupies the full 8-bit range of possible palette entries, so there is no room for other fixed colors. Software using this palette must draw their user interface elements with the same colors used to show pictures. Also again, it does not provide true grays.

Other common uses of software palettes

Grayscale palettes

Grayscale 8bits palette sample image.png Grayscale 8bits palette color test chart.png
All 256 colors in grayscale palette
Dark Bright

Simple palette made doing every triplet RGB primaries having equal values as a continuous gradient from black to white through the full available palette entries. Here is the 8-bit, 256 levels palette:

Grayscale 8bits palette.png

Used to display pure grayscale TIFF or JPEG images, for example.

Color gradient palettes

Palettes made of a continuous color gradient from darkest to lightest arbitrary hues. The pixel data is treated as if it were grayscale, but the color table plays with RGB color combinations, not only gray. The relationship between the original luminance and the mapped one can vary, but the lighting scale is preserved along all the palette entries.

One very common case of such palettes is the sepia tone palette, which gives an image an old fashioned and aged look (left). Another gradient example, based on blue hues, is presented here (right), but any hue or mixing of hues can be used. Many cell phones with built-in cameras have options to take colorized photos using this technique.

Color gradient map (sepia) palette sample image.png   Color gradient map (blue) palette sample image.png
Color gradient map (sepia) palette.png   Color gradient map (blue) palette.png
All 256 colors in color gradient palettes (example)
RedDark Bright
GreenDark Bright
BlueDark Bright

Adaptive palettes

Adaptative 8bits palette sample image.png Adaptative 8bits palette color test chart.png

Those whose whole number of available indexes are filled with RGB combinations selected from the statistical order of appearance (usually balanced) of a concrete full true color original image. There exist many algorithms to pick the colors through color quantization; one well known is the Heckbert's median-cut algorithm. Here is the 8-bit, 256 color palette used with the color test chart and the image sample above:

Adaptative 8bits palette.png

Adaptive palettes only work well with a unique image. Trying to display different images with adaptive palettes over an 8-bit display usually results in only one image with correct colors, because the images have different palettes and only one can be displayed at a time. Here is an example of what happens when an indexed color image is displayed with any color palette that is not its own adaptive palette:

Incorrect 8bits palette sample image.png

False color palettes

False colors palette sample image.png False colors palette color test chart.png
False color palette map
Dark Bright
False color palette comparison
Dark
#000000 magenta
#333333 blue
#666666 cyan
#999999 green
#CCCCCC yellow
#FFFFFF red
Bright

Arbitrary gradient color scales, usually 256 shades, with no relationship with real colors of a given image. They are employed to artificially colorize a grayscale image to reveal details and/or to map the pixel level values to amounts of some physical magnitude (potential, temperature, altitude, etc.)

Note, in the example above, that new details can be seen as blue over magenta in the background's dark areas of the original photograph.

Here is the 8-bit, 256 color gradient palette used with the color test chart and the image sample above:

False colors palette.png

There exist many false color palettes, some of them standardized, used mainly in scientific applications: astronomy and radioastronomy, satellite land imaging, thermography, study of materials, tomography and magnetic resonance imaging in medicine, etc.

Notes

See also

  1. The Palette Manager: How and Why It Does What It Does, the article is in Windows Write file inside self-extracting archive.
  2. https://docs.microsoft.com/en-us/windows/desktop/opengl/palettes-and-the-palette-manager
  3. House of Mabel: RISC OS 2

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