I usually welcome the added info on the colors to combine it with the elevation number esp. when the green is undulated.
In a challenging situation on a bumpy green you may have 'hills & valleys' and your ball may have to cross both kinds, each with different tilts.
The dots can show the direction and amount of slope but the colors will indicate the elevation in that area.
Compare two examples: #1) a long, strait putt on a flat incline, with a slight tilt left to right, that goes up 3 feet to #2) the same putt w/ identical distance & elevation on a bumpy green:
#2) For example, the ball on the undulated green will travel into a small hill which goes up and slopes left to right, then it rolls down into a small dip, or 'valley'.....
.......Then the ball continues out of the dip into a slope up hill a great deal, then hits a small dip again just before the hole, each with it's own tilts !
That's very different, even though the numbers on the aim are identical in both examples (#1 & #2).
Sure, the elevation and distance are the same, but a ball will respond in a different manner on each example.
Granted, this is not so common but the information provided by WGT on the topography is noteworthy, IMO.
A common technique for players is to switch to 'chip' grid, etc. and/or move the aim marker in those areas to see the change in elevation displayed, then make a note in your head. But the colors help in that regard without using the aim marker so extensively.
Pinehurst 6 24 foot Birdie undulated green
http://www.wgt.com/replay.aspx?ID=e7dad7c2-9b21-43ce-95ad-a3b7016f7ed8