The RGB Color Model: How Screens Make 16.7 Million Colors
Every pixel on your screen is three microscopic lights — red, green and blue. Vary each from 0 to 255 and mix: that's the RGB model. It is additive: more light means brighter color, and all three at maximum make white. This mirrors human vision, which samples the world through three cone types roughly tuned to long (red), medium (green) and short (blue) wavelengths.
Additive vs subtractive
Screens add light (RGB); print absorbs it (CMYK). That single difference explains most digital-vs-print color surprises — see digital vs print colors.
| Mix | Result |
|---|---|
| R + G | Yellow |
| G + B | Cyan |
| R + B | Magenta |
| R + G + B | White |
| none | Black |
Bit depth and gamut
Standard "8-bit per channel" gives 256 levels each — 16.7 million combinations. HDR pipelines use 10 or 12 bits for smoother gradients. Separately, the gamut question is which actual colors the three primaries can reach: sRGB is the web default; Display P3 is ~25% larger; Adobe RGB extends the greens for print work. The same rgb(255,0,0) is a different physical red in each space.
Gamma: why RGB values aren't linear
Stored RGB values are gamma-encoded to match human brightness perception — value 128 is not half the light of 255. Correct blending, averaging and 3D lighting require converting to linear RGB first, doing the math, then converting back.
Working with RGB
Convert RGB to any format with our tools: HEX, HSL, CMYK, LAB, OKLCH.