When to use which grease?
 

White grease?
Red grease?
"Regular grease?
Goose grease?

Is there a set of rules for what should be used for certain applications? Plastic on plastic? Alloy on alloy? I'm looking for guidelines for which product to use in which situation.

I have a pretty good idea when to use KY lube but after that it is all a guessing game.:D

I use Mobil 1 (Red) synthetic grease for wheel bearings and my polybronze bushings, use Swepco moly grease for the CV's (though I have some super grease a Pelicanite gave me that I will use next time I pull them apart)..

I use Redline CV/wheel bearing grease (CV-2), for just about everything that needs grease. I put the black grease that came with the CV joint rebuild materials in my CV joints.
For kitchen faucets/shower controls/etc. I use the special plumbers grease you find at OSH, the o-rings don't swell, I don't know what it is, but works great. Comes in a very small container.
At one point I was trying to buy Wurth HHS 20000 but it is now named Wurth HHS-K for the EPA. This is supposed to be good for door hinges/etc. I use Brad Penn for the engine mainly because it is cool to know about it but really... and has high zinc/etc. :-)

high pressures (wheel bearings, CVs) require a high pressure, now extreme pressure (EP), rated grease - usually black due to MbS2 in it

white grease is used to avoid dark stains

Bosch "red grease" is a very sticky, high temperature grease useful for distributors

Mike (der Lubemaster) can tell you more

Someday when I figure out how to use it safely and clean it up, I'll use Krytox in CV joints. Until then, it's Swepco Moly. I just got a tube of that Sachs grease to use on the transmission input shaft and guide tube. That stuff is great. I have a small tube of GT Grease, which is like gorilla snot, and for everyday use I like synthetic Tri Flow grease on things like the throttle linkage and the hood latch and light switch plungers.