I tested AlphaBlend on spell animation, it looks pretty good, removing the need to remake webm when you just need to colorize it.
I only wish there would be more control over the spell resistance animation for DefenceBuffSpell, ie a line like
dodge_effect={"gfx": AlphaBlend("magic_shield_webm", "magic_shield_webm", gray_shield(340, 330), alpha=True)}
would actually work, replacing the default one.