Seem embarrassed by a brightly coloured room (6)
I believe the answer is:
redden
'seem embarrassed' is the definition.
I can't judge whether this definition defines the answer.
'by a brightly coloured room' is the wordplay.
'by' says to put letters next to each other.
'a brightly coloured' becomes 'red' (red is often a bright colour).
'room' becomes 'den' (den is a kind of room).
'red' put next to 'den' is 'REDDEN'.
Can you help me to learn more?
(Other definitions for redden that I've seen before include "Evaluate the nature of (something)" , "Blush, colour accordingly" , "Reveal embarrassment in colourful way" , "Blush or become flushed" , "Blush like the dawn sky" .)