Yellow as some supermarket chickens? (7)
I believe the answer is:
gutless
'yellow' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for gutless that I've seen before include "Cowardly, lacking intestines" , "Chicken-livered" , "Lacking courage and determination" , "Showing no evidence of bottle" , "racket like this is not much use" .)