Don't go well together, as colors (5)
I believe the answer is:
clash
(Other definitions for clash that I've seen before include "Mismatch" , "Loud noise - conflict" , "Disagree violently" , "Forceful disagreement" , "Fail to fit" .)
I believe the answer is:
clash
(Other definitions for clash that I've seen before include "Mismatch" , "Loud noise - conflict" , "Disagree violently" , "Forceful disagreement" , "Fail to fit" .)