This is a list of 8-bit computer color palettes, and graphics, which were primarily manufactured from 1975 to 1985. Although some of them use RGB palettes, more commonly they have palettes of 4, 16, or more colors that are neither bitwise nor intensity-level combinations of the RGB primaries, but instead consist of fixed colors defined by ROM or dedicated circuitry and selected by the manufacturer. Due to mixed-bit architectures, classifying these systems solely by their "n-bit" designation is not always precise. Another error is assuming that a computer's color palette represents what it can show all at once. Resolution is also a crucial aspect when criticizing an 8-bit computer, as many offer different modes with different amounts of colors on screen, and different resolutions, with the intent of trading off resolution for color, and vice versa.

Sample image Color test chart 3-bit, 8-color palette 6-bit, 64-color palette

3-bit RGB palettes

Systems with a 3-bit RGB palette use 1 bit for each of the red, green and blue color components. That is, each component is either "on" or "off" with no intermediate states. This results in an 8-color palette ((21)3 = 23 = 8) that have black, white, the three RGB primary colors red, green and blue and their correspondent complementary colors cyan, magenta and yellow as follows:

|Sample image |Palette coverage |Color indexes

The color indices vary between implementations; therefore, index numbers are not given. A common selection has 3 bits (from LSB to MSB) directly representing the 'Red', 'Green' and 'Blue' (RGB) components in a number from 0 to 7. An alternate arrangement uses the bit order 'Blue', 'Red', 'Green' (BRG), such that the resultant palette - in numerical order - represents an increasing level of intensity on a monochrome display.

The 3-bit RGB palette is used by:

The ECMA-48 standard for text terminals (sometimes known as the "ANSI standard", although ANSI X3.64 does not define colors) Teletext Level 1/1.5 Teletext. Videotex Oric computers BBC Micro The original NEC PC-8801 up to the MkII The original NEC PC-9801 with original 8086 CPU before the VM/VX models All Sharp X1 models before the X1 Turbo Z The Sharp MZ 700 Fujitsu FM-7, FM New 7, FM 77 before the FM77AV Sinclair QL The Macintosh SE with a color printer or external monitor The SECAM version of the Atari 2600 The Color Maximite, a PIC32 based microcomputer The Thomson TO7 (with spatial constraints – only 2 colors for each group of 8×1 pixels) The Matra Alice 32 and 90 The Philips VG5000

Specific details about implementation and actual graphical capabilities of specific systems, are listed on the next sub-sections.

World System Teletext Level 1

World System Teletext Level 1 (1976) uses a 3-bit RGB, 8-color palette. Teletext has 40×25 characters per page of which the first row is reserved for a page header. Every character cell has a background color and a text color. These attributes along with others are set through control codes which each occupy one character position. Graphics characters consisting of 2×3 cells can used following a graphics color attribute. Up to a maximum of 72×69 blocky pixels can be used on a page.

Simulated image

BBC Micro BBC Micro has 8 display modes, with resolutions like 640×256 (max. 2 colors), 320×256 (max. 4 colors) and 160×256 (max. 16 logical colors). No display modes have cell attribute clashes. The palette available has only 8 physical colors, plus a further 8 flashing colors (each being one of the eight non-flashing colors alternating with its physical complement every second), and the display modes can have 16, 4 or 2 simultaneous colors.

Simulated image

BBC Micro display modes

| Mode 0 (640 × 256, 2 colors) | Mode 1 (320 × 256, 4 colors) | Mode 2 (160 × 256, 8 colors)

| Mode 4 (320 × 256, 2 colors) | Mode 5 (160 × 256, 4 colors) | Mode 8 (80 × 256, 8 colors)

Sinclair QL (Sinclair Quantum Leap)

On the Sinclair QL two video modes were available, 256×256 pixels with 8 RGB colors and per-pixel flashing, or 512×256 pixels with four colors: black, red, green and white. The supported colors could be stippled in 2×2 blocks to simulate up to 256 colors, an effect which did not copy reliably on a TV, especially over an RF connection. Pixel aspect ratio was not square, with resulting image proportions close to 4.4:3, making the image extend into the horizontal overscan area of a CRT TV.

| 256 × 256 mode | 512 × 256 mode

| Simulated images (aspect ratio corrected)

| Simulated images (original pixel size)

{|class="wikitable" style="width: 20pc" ! style="color:black; background:white;"| 256×256 ! style="color:black; background:white;"| 512×256 |- | style="color:white; background:#000000;"| black | style="color:white; background:#000000;" rowspan="2"| black |- | style="color:white; background:#0000ff;"| blue |- | style="color:black; background:#ff0000;"| red | style="color:black; background:#ff0000;" rowspan="2" | red |- | style="color:black; background:#ff00ff;"| magenta |- | style="color:black; background:#00ff00;"| green | style="color:black; background:#00ff00;" rowspan="2"| green |- | style="color:black; background:#00ffff;"| cyan |- | style="color:black; background:#ffff00;"| yellow | style="color:black; background:#ffffff;" rowspan="2"| white |- | style="color:black; background:#ffffff;"| white

PC-8000 series The NEC PC-8000 was capable of displaying graphics with a resolution of 160x100 pixels and 8 colors.

4-bit RGBI palettes

The 4-bit RGBI palette is similar to the 3-bit RGB palette but adds one bit for intensity. It contains variants of colors (dark or bright on most machines, but saturated or unsaturated was also possible) potentially giving a total of 23×2 = 16 colors. Some implementations had only 15 effective colors due to the "dark" and "bright" variations of black being displayed identically. Others generated a grey tone or a different color.

This 4-bit RGBI schema is used in several platforms with variations, so the table given below is a simple reference for the palette richness, and not an actual implemented palette. For this reason, no numbers are assigned to each color, and color order is arbitrary.

Systems that used this palette scheme:

IBM's original Color Graphics Adapter IBM's Enhanced Graphics Adapter, in CGA modes Tandy graphics on IBM's PCjr and Tandy 1000-series computers Plantronics Colorplus on a limited number of PC-compatible computers MCGA and VGA graphics standards for backward compatibility Commodore 128 series for its 80-column mode ZX Spectrum (and compatible) (with spatial constraints – only 2 colours for each group of 8x8 pixels) CPC 464/664/6128 Sharp MZ-800 series computers Thomson MO5 and TO7 (with spatial constraints – only 2 colours for each group of 8x1 pixels)

Specific details about implementation and actual graphical capabilities of specific systems, are listed on the next sub-sections.

ZX Spectrum

The ZX Spectrum (and compatible) computers use a variation of the 4-bit RGBI palette philosophy. This results in each of the colours of the 3-bit palette to have a basic and bright variant, with the exception of black. This was accomplished by having a maximum voltage level for the bright variant, and a lower voltage level for the basic variant. Due to this, black is the same in both variants.

The attribute byte associated with every 8×8 pixel cell comprises (from LSB to MSB): three bits for the background colour; three bits for the foreground colour; one bit for the bright variant for both, and one bit for the flashing effect (alternate foreground and background colours every 0.32 seconds). Thus the colours are not independently selectable as indices of a true palette (there are not colour numbers 8 to 15, and the bright bit affects both colours within a cell). However, within a single set of 8 colours the BRG order of bits means that the colours appear in increasing order of brightness on a monochrome display.

The colour number (0 to 7) can be employed with the following BASIC statements to choose:

BORDER n, the colour for the surrounding area outside the pixel graphical area. This cannot use the bright variants. PAPER n, the background (pixel bit value of 0) colour for an 8×8 pixel cell. INK n, the foreground (pixel bit value of 1) colour for an 8×8 pixel cell.

And a value of 0 or 1 with the following statements to choose:

BRIGHT n, sets the bright bit for both foreground and background colours in an 8×8 pixel cell. FLASH n, sets the bit that controls the flashing effect in an 8×8 pixel cell.

| Simulated image | colspan="3"|Sample image and palette

| style="vertical-align:top;" | |} ZX Spectrum Hardware PaletteColour numberBinary valueColour nameBinary valueColour nameGRBIGRBI00000Black0001Black10010Blue0011Bright Blue20100Red0101Bright Red30110Magenta0111Bright Magenta41000Green1001Bright Green51010Cyan1011Bright Cyan61100Yellow1101Bright Yellow71110White1111Bright White

Some ZX Spectrum clones or NTSC machines might display "bright black" as dark gray. Colours simulated as sRGB assume non-bright as 85% voltage (0.55 V) and bright as 100% (0.65 V). Each ZX Spectrum model used different voltages, so the colours shown are only approximate.

IBM PC/XT and compatible systems

The original IBM PC launched in 1981 features an Intel 8088 CPU which has 8-bit data bus technology, though internally the CPU has a fully 16-bit architecture. It was offered with a Monochrome Display Adapter (MDA) or a Color Graphics Adapter (CGA). The MDA is a text mode-only display adapter, without any graphic ability beyond using the built-in code page 437 character set (which includes half-block and line-drawing characters), and employed an original IBM green monochrome monitor; only black, green and intensified green could be seen on its screen. Then, only the CGA had true graphic modes.

The IBM PC XT model, which succeeded the original PC in 1983, has an identical architecture and CPU to its predecessor, only with more expansion slots and a hard disk equipped as standard. The same two video cards, the MDA and the CGA, remained available for the PC XT, and no upgraded video hardware was offered by IBM until the EGA, which followed the introduction of the IBM Personal Computer/AT, with its full 16-bit bus design, in 1984.

CGA

The Color Graphics Adapter (CGA) outputs what IBM called "digital RGB"Richard Wilton, Programmer's Guide to PC & PS/2 VIDEO SYSTEMS, 1987, Microsoft Press. (that is, the R, G, B (and I) signals from the graphics card to the monitor can each only have two states: on or off).

CGA supports a maximum of 16 colors. However, its 320×200 graphics mode is restricted to fixed palettes containing only four colors, and the 640×200 graphic mode is only two colors. 16 simultaneous colors are only available in text mode or the "tweaked text" 160×100 mode.

A different set of 16 simultaneous colors is available using an NTSC TV or composite monitor by using artifact color techniques, with independent groups having demonstrated much larger color sets of over 256 colors See Color Graphics Adapter#High color depth.

The CGA RGBI palette is a variant of the 4-bit RGBI schema, arranged internally like this:. CGA palette internal bit arrangement (4-bit RGBI)ColorIRGBColorIRGBBlack0000Gray 21000Blue0001Light Blue1001Green0010Light Green1010Cyan0011Light Cyan1011Red0100Light Red1100Magenta0101Light Magenta1101Yellow / Brown0110Light Yellow1110Gray 10111White1111