I've done my research, and now I just need to tighten the options a bit so I know which direction I should consider going. What I intend to make is a mod which applies a blush effect to the face in two steps, meaning two different blush textures, with the second designed to merge appropriately with the first (as opposed to replacing). From what I gather, there are at least three ways of going about this:

1: Custom mesh that hugs the player's face. Serious pitfalls to this approach. The mod called "Edialog" uses this method and the results often highlight the inherent problems.

2: Effect shader. "Bloody Facials" uses this approach and I still don't quite grasp how it tells the CK to apply the effect to the face. But there are unavoidable issues with this method. For starters, there's a glow-in-the-dark effect that may or may not be solvable. It also seems that textures applied to the face also get applied to the body. I'm not certain about either of these concerns, though.

3: Usurp a couple of face tints which hopefully weren't already being used.

I am leaning towards option 3 because option 1 is hopeless and option 2 may have the issues I outlined. (And I doubt option 2 would allow two textures at once.) But I would be very interested to know what folks think would be a good way of accomplishing what I'm after. Some specifics:

* The blush textures have an alpha channel.

* The idea is to have them fade in / fade out over a set time, rather than instantly appearing and disappearing, which means I need alpha control over them.

* Would prefer not having to deal with bizarre format constraints. For example, I tried replacing one of the warpaints with one of my blush textures and it definitely did not work in-game, presumably because I had violated some limitation of the warpaint specifications.

Would also like to know which two tints folks feel would be the most underused by players in general.

Thanks in advance!