Ruddy embarrassed? (3)
I believe the answer is:
red
This clue is a double definition.
'ruddy' is the first definition.
(I know that ruddy can be written as red)
'embarrassed?' is the second definition.
(someone may blush or go red when embarrassed)
(Other definitions for red that I've seen before include "Primary colour" , "'If you see it, perhaps you're angry (3)'" , "Blushing" , "Scarlet or vermilion" , "The colour of the former Russian army" .)