If making your boots look cool is easy (it is), takes up time that could really only be spent masturbating (it's not ski season anymore), and doesn't cost an arm and a leg (25 bucks or so), why not do it?
To OP, you cant dye them if they are black, but you could:
1. take them apart (be careful to not strip the screws, and keep the left and right parts separate)
2. sand the pieces you want to paint
3. paint them with grey or white primer
4. let dry and lightly sand the primer coat
5. do a coat of red
6. lightly sand the red coat
7. do another coat of red
8. use ultra fine scuffing pads (replacement for 0001 steel wool) to buff the last coat of paint
9. put your boots back together (pretty easy to figure out where everything goes)
10. look like a boss (or probably just a wallisch impersonator)
If the spray paint starts to chip, which it probably will, your boots will look pretty beat up by the end of the season.
The good news is that spray paint is remarkably easy to remove from FT boots, and if at the end of next season, you are bored with your boots again, you can start the process over.
I'm currently working on a write up for spray paint removal, dyeing, and restoring FTs in general. Hopefully that helps some people out, because I've searched NS, TGR, and Google pretty intensively, and the information available on boot customization is scattered and unhelpful at best.
If this was just a troll thread because you want to make fun of kids who dye their boots. . .