Your code ran fine for me but it is changing the background color - not the text color. I'd change the order of the second and third case statements as 100% is greater than zero. The case statement stops at the first true, so it never reaches the 100.

A quick search also turned up:
https://msdn.microsoft.com/en-us/lib.../ff862901.aspx

The FontEx method allows you to use the PJ colors

https://msdn.microsoft.com/en-us/lib.../ff862872.aspx