Making solution difficult, see the tutorial by Gaieus I ref above

Good job! Thanks!

I think your modified textures have to be saved in some way as unique textures because of their different color assignments. I did it once, recently, but I stumbled on the desired result, rather than remembered the procedure. Do a search say in Google on keywords: Sketchup create unique textures. That is what I will be doing at some point. Or, help.sketchup.com search "textures"

You can always set the shortcuts to something you are more familiar with.
Window/Preferences/shortcuts.