Hexahue

Hexahue was invented by Josh Cramer. He was inspired to come up with a unique alphabet that could substitute standard English writing for combinations of colours that were easily able to be distinguished. Hexahue uses only colour combinations of 100% brilliances, 100% absences, and 50% brilliance/absence of all colours, which is mid-gray. Hexahue colours are more "commonly" recognized colours, with "common" names, and yet they are simple to write in HTML notation.

Notable features

Type of writing system: alphabet.
Direction of writing: left to right in horizontal lines, but can be written in other directions
Used to write: English
Consists of 9 unique colours: red, green, blue, yellow, cyan, purple, black, mid-gray, and white.
Letters are written in 2x3 squares with incrementing patterns of 6 of the colours (red, green, blue, yellow, cyan, and purple).
Numbers are written with incrementing patterns of 3 of the colours (Black, Gray, White).
Punctuation is written with two variations of black and white "checkers" built into 2x3 squares.