HighColor

Highcolor, in the context of computer graphics, refers to a historical color depth classification for displays that use 16 bits per pixel. It most commonly denotes 15 or 16 bits of color information per pixel, enabling a palette of roughly 32,768 to 65,536 distinct colors depending on the exact layout. The two most common pixel formats associated with highcolor are 5-6-5 (red 5 bits, green 6 bits, blue 5 bits) and, less frequently, 5-5-5.

In practice, highcolor sits between 8-bit color systems (PseudoColor) and truecolor systems with 24 or 32 bits per pixel. Visuals labeled highcolor could implement colors either via direct color bitfields or through a small color palette, depending on hardware and driver support. Because the mapping from bit patterns to actual colors could vary by system, highcolor offered more colors than 8-bit designs but did not guarantee the full, consistent color fidelity of later 24-bit truecolor modes.

Today, highcolor is largely a historical term. As display technology and graphics software evolved, 24-bit or 32-bit truecolor became the standard, offering a fixed 8 bits per color channel and far greater color accuracy. The concept remains relevant for understanding older graphics systems, drivers, and windowing environments that used 16-bit color modes.

See also: TrueColor, DirectColor, PseudoColor, Visual (X11).