First thing you need to do is look at the green speed. Colors I pay no attention to simply the elevation difference for example 10" up or 10" down. after that it's a simple equation for me...I add one foot per inch of up elevation or minus one foot per down, that's for standard speed greens so I compensate by feel for slower or faster than standard.
As for break it's mostly all feel, watch the speed of the grid movement, over four feet I'll move my aiming marker according to how many dots and how fast they move. it's a gut feeling really. Putts inside four feet or extremely slow movement on the grid I will just compensate with my swing meter and not move my aiming marker.
Personally I like fast greens, seems I can judge everything better and with more touch. The slower greens make me feel sort of barbaric having to smash putts and I still end up short on many putts outside the five or six foot range. Slow greens also seem to exponentiate the equation, say I have a five footer I will hit the ball at the six or seven foot meter mark but on a 20 footer I will have to hit it on the 24 or 25 foot mark.