I changed Windows allocation policy to 'high address first' using registry - set HKLM\\System\\CurrentControlSet\\Control\\Session Manager\\Memory Management\\AllocationPreference = 0x100000 and restart computer. (see http://msdn.microsoft.com/en-us/library/bb613473%28v=vs.85%29.aspx for more details) After that all VAX coloring of C++ code in VS2008 has disappeared. It doesn't react on VAX options change or symbols DB rebuild. Coloring in VS2010 is not affected and works fine.
After removing AllocationPreference key from registry and one more restart coloring has returned. But I need that option to test x64 mode of our application, so I ask you to investigate if this problem may be fixed.