This is a common request, and, trust me, we have researched it.
Allow me to elaborate on some of the issues:
1) #else and #if 1 ... #else ...: How should these be colored? Example:
1 #if 0
2 H1
3 #else
4 H2
5 #endif
Should just line 2 be colored as a comment? Or lines 1,2,and 3? Or just lines 1 and 2?
2) The slippery slope. If we forced color coding to special case #if 0,
then within two days, someone would invariably ask us to support:
#ifdef NOT_DEFINED
...
#endif
3) The sledgehammer: Treating a #if 0 block like a comment is something of a sledgehammer.
SlickEdit's most powerful features like tagging and smart paste, get really dumb if they
think you are in plain text (that is, within a comment). The right solution is requires a
more powerful mechanism to highlight the inactive region without losing it's color properties.
The alternative: The current solution is to use selective display of preprocessing to
hide all your inactive #if regions. View > Selective Display..., Preprocessing.