We found 21 dictionaries that define the word colours:

General (15 matching dictionaries)

1. colours: Merriam-Webster
2. colours: Collins English Dictionary
3. colours: Vocabulary.com
4. Colours, colour's, colours: Wordnik
5. colours: Cambridge Advanced Learner's Dictionary
6. colours: Wiktionary
7. colours: Dictionary.com
8. Colours (Adam F album), Colours (Ayumi Hamasaki album), Colours (Baccara album), Colours (Blue album), Colours (Christopher album), Colours (Donovan song), Colours (EP), Colours (Eloy album), Colours (Graffiti6 album), Colours (Grouplove song), Colours (Hot Chip song), Colours (Michael Learns to Rock album), Colours (Nadia Oh album), Colours (Resurrection Band album), Colours (Sam Rivers album), Colours (TV channel), Colours (film), Colours (solitaire), Colours: Wikipedia, the Free Encyclopedia
9. colours: Rhymezone
10. Colours: E Cobham Brewer, The Reader's Handbook
11. Colours, Colours, Colours, Colours: Dictionary of Phrase and Fable (1898)
12. colours: FreeDictionary.org
13. colours: Mnemonic Dictionary
14. colours: TheFreeDictionary.com
15. colours: Longman Dictionary of Contemporary English

Art (1 matching dictionary)

16. An Illustrated Dictionary of Jewelry (No longer online)

Computing (1 matching dictionary)

17. colours: Encyclopedia

Medicine (1 matching dictionary)

18. colours: Merriam-Webster Medical Dictionary

Miscellaneous (1 matching dictionary)

19. Brilliant Dream Dictionary (No longer online)

Slang (2 matching dictionaries)

20. colours: Green’s Dictionary of Slang
21. C.O.L.O.U.R.S, c.o.l.o.u.r.s, colours: Urban Dictionary

(Note: See colour as well.)

Definitions from Wiktionary (colours) ▸ noun:  (nautical) Flag denoting the nationality of a vessel, flown from the stern. Similar: Colors, house flag, pendant, pennant, quarter badge, pair of colours, badge, pair of colors, flag, escutcheon, more... Opposite: monochrome, grayscale, colorless, achromatic, neutral Types: red, green, blue, yellow, orange, purple, white, grey, brown, pink, more... Phrases: primary colours, true colours, water colours, flying colours, complementary colours, more... Adjectives: different, various, bright, many, true, primary, brilliant, water, vivid, darkest, beautiful ▸ Words similar to colours ▸ Usage examples for colours ▸ Idioms related to colours ▸ Wikipedia articles (New!) ▸ Popular adjectives describing colours ▸ Words that often appear near colours ▸ Rhymes of colours ▸ Invented words related to colours