Bedeutung von “blue” — Learner’s Dictionary

blue

noun [ C, U ] us uk /bluː/
The sky was a brilliant blue.The sky deepened to a rich, dark blue.He can't differentiate between blue and green.Blue is meant to be very calming.We decided on blue for the bathroom.

A2 the colour of the sky when there are no clouds

(Definition von “blue noun” aus dem Cambridge Learner's Dictionary © Cambridge University Press)