Numbers › Hexadecimal

Hexadecimal (base 16)

Base 16 — A through F take over after 9. The system that names every CSS colour.

Hexadecimal — base 16

Computers count 0–9, then A–F (10–15). Three pairs of hex digits make a colour.

#FF8833

R (red)

FF (255)

G (green)

88 (136)

B (blue)

33 (51)

How hex digits work

Hex uses 16 symbols: 0–9 for ten through fifteen we use A B C D E F. The number 1A is 16 + 10 = 26. The number FF is 15·16 + 15 = 255.

Why every colour is six hex digits

A colour has three channels (red, green, blue), each from 0 to 255. 255 in hex is FF — which is just two characters. Six characters total is enough for the whole palette.