- the flag that indicates nationality
- the ceremony of hoisting or lowering the colours
- a pair of silk flags borne by a military unit, esp British, comprising the Queen's Colour showing the unit's crest, and the Regimental Colour showing the crest and battle honours
- true nature or character (esp in the phrase show one's colours)
- a distinguishing badge or flag, as of an academic institution
- a badge or other symbol denoting membership of a team, esp at a school or college
- a distinguishing embroidered patch denoting membership of a motorcycle gang
- nail one's colours to the mast
- to refuse to admit defeat
- to declare openly one's opinions or allegiances
