Meaning of “colourless” - Learner’s Dictionary

colourless

adjective UK (US colorless) uk us /ˈkʌlələs/
COLOUR

without any colour:

a colourless liquid
INTEREST

without the qualities that make someone or something interesting and unusual:

a colourless account of his time in parliament

(Definition of “colourless” from the Cambridge Learner’s Dictionary © Cambridge University Press)