Dinwiddie poured in a career-high 21 points and added seven assists while Johnson contributed 19 points and nine rebounds for Colorado (17-7, 7-5 Pac-12).
The victory was the third straight and sixth in seven games for the Buffaloes.
The Wildcats (20-4, 8-4), who lost Sunday to California, got 12 points and seven rebounds from Solomon Hill and 11 points from Mark Lyons.
Toddler uninjured after being knocked over by Obama family dog
Man spent 15 hours in jail for plugging electric car into an outlet at a school