Hex versus RGB

#RRGGBB and rgb(r, g, b) are two writings of the same three channels. The hex to RGB converter maps each pair of hex digits to an integer from 0 through 255. #ff0000 is rgb(255, 0, 0). #00ff00 is rgb(0, 255, 0). #0000ff is rgb(0, 0, 255).

Hex is compact, so design tools and CSS authors lean on it. RGB integers are easier to read when you are mixing a wash of blue and want to nudge one channel. Neither form is “more accurate” on this page. They name the same 24-bit color.

The converter expects six hex digits, with or without the hash mark. #fff and the word red are rejected. Expand a short hex code yourself (#ffffff for white) or type the three integers. A bad string is an error on the hex field, not a guessed nearest color.

Each RGB channel must be a whole number from 0 through 255. 256, a decimal, or a blank box is an error on that channel. When the three integers are valid, the hex field updates and the swatch paints that color.

If you are matching a brand chip, copy both writings from the result. Paste hex into a CSS file and RGB into a tool that wants three numbers. They should stay in lockstep after one conversion.