colorindex
Color index, sometimes written as colorindex, is a numerical value used to select a color from a predefined palette or color lookup table (LUT) in digital images and graphics. In an indexed color system, each pixel stores a small integer, commonly 0–255, which points to a color in the palette. The palette itself contains the actual color definitions, typically as RGB triplets, and may also include an alpha channel in some formats.
In practice, color indexing separates image data (the indices) from color data (the palette). This allows compact
Color indexing trades color fidelity for efficiency. The process of choosing the palette is called color quantization,
Today, most consumer images use true color (24-bit or higher), but indexed color remains common in certain
Terminology related to color indexing includes palette, color map, and LUT. These terms describe the collection