Changing color scheme

I really like the concept of indicating when someone has gone past 6 hours and needs to slow down. The trouble is that it makes the board harder to interpret when glancing at it. Yellow shouldn't represent both an "okay, but work a little more towards green" and "you're past green, better slow down". Same principle holds true for red too.

I propose this tweak:
0.0-3.9 - white or no dot
4.0-4.9 - blue, preferably Detroit Lions blue
5.0-5.9 - green
6.0-6.9 - yellow
7.0+ - red