Other forms: colours, coloured, colouring
Colour is what your eyes report about light — the red of a postbox, the grey of the sky before rain, the exact green of a tennis ball. Colour is the British spelling; American English writes color, and the swap carries through to colourful, coloured and colouring.
In the diamond trade colour is one of the four Cs, and there it is a grade rather than a hue: stones are lettered from D, which is colourless and worth the most, down through the faint yellows and browns. So 'a good colour' in a jeweller's window means almost no colour at all. As a verb, colour is what a child does to a picture and what a bad experience does to your judgement — the argument coloured everything she said afterwards. It is also what a face does: he coloured and looked away. In the plural, colours means a flag or an emblem, which is where passing an exam with flying colours comes from. One thing to avoid: coloured used of a person is offensive in Britain and the United States, and people of colour is the phrase in use.
1nounhueThe quality of light that makes something look red, blue, green and so on.
“The colour of the paint changes as the sun moves round.”
2noungradeIn the jewellery trade, a grade showing how near to colourless a stone is.
“The stone is a fine colour but the cut lets it down.”
3nounpluralChiefly in the plural, a flag or emblem standing for a country, ship, team or regiment.
“The regiment marched behind its colours.”
4verbgiveTo give colour to something, or to fill it in with colour.
“She coloured the whole map in with two pencils.”
5verbinfluenceTo influence the way something is seen or judged.
“One bad meeting coloured his view of the company for years.”
6verbfaceOf a person, to go red in the face.
“He coloured when they read his name out.”
Too few real examples of this word to estimate which sense is commonest.
Also accepted in games: color grade
Middle English
colour
English
color
English, today
colour
color comes from Middle English colour. From Middle English colour, color, borrowed from Anglo-Norman colur, from Old French colour, color, from Latin color. a doublet of couleur. Largely displaced English blee, Middle English blee (“color”), from Old English blēo. Also partially replaced Old English hīew (“color”) and its descendants (English hue), which is less often used in this sense.
Etymology from Wiktionary, CC BY-SA