Apologies for this, I am seeing the same problem. There is something about Windows 8.1 that is triggering this problem. Colouring works correctly for me in Windows 7 and Windows 8.
This problem isn't solved in Release 2036 ? (Windows 8.1, Visual Studio 2010)
VA_X.dll file version 10.8.2036.0 built 2014.05.22 DevEnv.exe version 10.0.40219.1 Professional msenv.dll version 10.0.40219.1 Comctl32.dll version 6.10.9600.17031 Windows 8 6.2 Build 9200 4 processors (x86-64, WOW64) Language info: 1252, 0x407
Unfortunately this has not yet been fixed. We are still aware of this, and looking into this, but its not yet clear how best to fix this. This thread should be updated when this has been fixed.