Say you want to plot two TH2Ds with on the same pad but different color paletettes?

This is possible, but requires a touch of fancy ROOT-ing. Actually, it's not that much, it just takes a lot of time to figure it out. So here it is.

Fair warning, the order of all the gPad->Modified's etc seems very important to no seg fault.

In include the main (demo.cc) and the Makefile.