True Color ( engl. For true color ) is a term used in computer technology ( graphics card ) and denotes a color depth of 24 bits (3 x 8 bits, corresponding to 2 24 ≈ 16,780,000 colors). Images of this color depth give the human viewer a natural impression.
The representation is in the RGB color space with eight bits each (256 gradations) for the red , green and blue components . Adjacent colors that differ from each other by only one level of intensity per color component are difficult to distinguish by the human eye. With spatially extended color gradients between very similar colors, however, gradations are more or less clearly recognizable.
True Color is often used with a color depth of 32 bits. However, only 24 bits are included in the actual image display, the remaining 8 bits either serve as an alpha channel (for graphic files) or are not used at all (for the actual screen display). This arrangement is chosen more often than the one with 24 bits, because 32 as a power of two enables a simpler addressing logic - all red color values are located at memory addresses which can be divided by 4 and which can be calculated by bit shifting . With addresses divisible by 3, as used in the real 24-bit mode, a slower multiplication must be carried out and memory accesses become slower due to misalignment .
Another color depth that only uses 15 or 16 bits to encode the color information is high color . Deep Color, on the other hand, uses 10 bits per color channel and is supported by Windows 7 or OS X El Capitan and newer operating systems, assuming suitable hardware .