Not even a close call here.
The Hustler was, by far, a better movie than Color of Money by every measurable level; storyline and script, cast ( Newman in his prime, Gleason, Scott), depth and complexity of characters, cinematography (black and white was better suited for the film), even the pool scenes were of better quality.
The Hustler is one of the best movies ever made, and it wasn't just about pool; it was about life, love, good vs evil, conflict, personal inner struggle, human character at every level. It made me laugh, cry, happy, sad, proud, and ashamed.
On the other hand, although I enjoyed the pool parts, the Color Of Money was kid stuff. JMHO
Jim