I don’t know what they are called, but bakashi uses them a lot, and sells them.
http://forums.gameaxis.com/showthread.php?t=1513682
What?! No Green 
Powder coat will last a long time (years if not for a lifetime) and hold up best but in a jiff an enamel-based paint (Rustoleum for metal) will do, too.
Vinyl paint is plastic-based and WILL peel off like plastic, too. Don’t see that adhering well to metal.
Do not mix paints and use on the wrong surfaces… Word of caution
It’s nice that he has these screws, but honestly $11-$13 for just 6 of these things?
IF you look online, you can get M4 cap sockets/button heads in lots of 25, 50, and 100 for a lot less than that!
Vynyl Dye should never be used for metal. The way it works is by soaking into the material you’re using it on. If the plastic parts have a shiny coating on them, you may have to do minor sanding to get the dye past the coating to properly soak into the material. But, yeah, don’t use it on metal. You also want ventilation when you use it!
I yet to find green, you can paint the screw heads with a paint suitable for metal like Rustoleum.
I ordered Red, Blue and Purple, as well as 2 non anodized bolts, one hex other is philips.
I am keeping a set of Blue for my TE S.
You can use any car paint (spray or not doesn’t really matter) for the screws. I’ve used black w/ clear finish on my screws; since it’s made for aluminium / metal surfaces, there won’t be any problems with the paint chipping off.