Brand & Design
What is RGB?
A color model that represents colors as additive combinations of red, green, and blue light, used by every digital screen.
Also known as: Red Green Blue
RGB describes a color by how much red, green, and blue light to mix. In CSS: rgb(37 99 235) or rgb(37, 99, 235). Each channel is 0-255 (8 bits) by default; CSS now also accepts percentages and float values for higher-precision color spaces. Add an alpha channel and you have RGBA: rgb(37 99 235 / 0.5) for 50% opacity.
RGB is additive (more light = brighter, all three at maximum = white) which matches how screens emit light. Print uses CMYK, which is subtractive. Converting between the two is lossy: RGB can produce vivid colors that fall outside the CMYK gamut, and CMYK can produce some dark colors RGB cannot reproduce. Brand kits typically declare both versions of the primary color with explicit values for each.
For programmatic color work, RGB is the universal lingua franca: every image format, every screen, every drawing API speaks it. For perceptual work (gradients that look smooth, accessible contrast ratios), HSL or OKLCH are better, with RGB as the final output stage.
In the wild
- →
rgb(255, 0, 0)for pure red on a screen - →A Sketch palette exporting brand colors as both hex and RGB so engineers can paste either
- →An accessibility check converting RGB to relative luminance to compute contrast ratio against text
How Brand.dev uses rgb
Endpoints in the Brand.dev API where this concept comes up directly.
FAQ
RGB vs sRGB?
sRGB is the specific RGB color space (gamut + gamma curve) that the web defaults to. When CSS says "RGB," it means sRGB unless you opt into a wider gamut with color(display-p3 ...).
How do I convert hex to RGB?
Split the six hex digits into three pairs, parse each pair as a base-16 number. #2563eb becomes rgb(37, 99, 235). Every language and design tool has a one-liner for this.
What is RGBA?
RGB plus an alpha channel for transparency: rgba(0, 0, 0, 0.5) is 50% opaque black. Modern CSS also accepts the slash syntax: rgb(0 0 0 / 0.5).
Related terms
A six-digit (or three-digit) hexadecimal representation of a color's red, green, and blue components, the most common way to write colors in CSS and design tools.
A subtractive color model used in print that mixes cyan, magenta, yellow, and black inks to produce colors on paper.
A standardized spot-color system used in print, where each color is a pre-mixed ink with a globally consistent reference number (e.g., Pantone 286 C).
The defined set of colors a brand or design system uses, typically organized into primary, secondary, neutral, and semantic groups.
Cascading Style Sheets, the language browsers use to style HTML: colors, typography, layout, animation, and responsive behavior.