Having many different colours, not just one. A multicoloured scarf, a multicoloured bird, multicoloured lights. This is the British spelling; American English writes multicolored. Though actually it does not mean every colour in the rainbow — it just means several colours together, often bright ones. It is an ordinary describing word, fine in speech and writing. Colourful is close, but colourful can mean full of colour even when the colours are few; multicoloured pushes the idea of many colours side by side.