Where on uesp info pages can I find...

[Chicken Slayer]

...description of visuals for various effects, such as spell reflection, absorption, and resistance.

Specifically I want to know what is happening when a lich turns purple (or not). Is that only spell reflection? Can I tell if it is absorbing?
I'm testing poison damage shot from an enchanted bow and I can tell when I get components reflected back on me by icons showing on my screen, but is there some visual to indicate absorbtion is taking place, or hitting magic resistance?

[Imbalance]

I don't think I've seen that kind of description on any wiki, come to think of it. I remember SR71 adding certain magical effects to his spell concoctions strictly for the appearance of the graphics, but nothing in the way of a guide to visual cues. I could see such a thing being useful.

There was a time I could remember some of them just from playing, but too many other games have overwritten that brain data. In Morrowind, at least, color was an indication of which school of magic the spell belonged to, but i don't remember if that was always accurate. Poisons in Oblivion cause a greenish effect most of the time, but I seem to remember some being a burgundy color? Plus, some spells were green, but I don't think they were school-based...?

Sorry, I'm not much help.

[Chicken Slayer]

This is getting really complicated. A lich can turn pink, have a purple plasma cloud, have red sparkles, and/or snowflake sparkles. I switched to testing on a Xivilai, which only has Absorb spell (turns pink and has red sparkles). But it does not always turn pink when it absorbs light, and it can have sparkles when it doesn't turn pink (I think). My bow is enchanted with light, command creature, weakness to poison and weakness to magic. The absorption is triggered by each enchantment separately, so some can be absorbed and some not on any one shot.
I suspect the game misses turning on an effect some times (I found something like this when testing gates when the game went "off script").
I don't have a character with 100% absorb magic that I could watch take hits in 3D mode

[Chicken Slayer]

I think I've got the basics figured out. When a lich absorbs a spell it turns pink and sparks fly off (Xivilai do this). When it reflects a spell component it turns pink and a pink and purple plasma cloud swirls around. When the player is hit with the reflected spell, a spell-specific visual can appear. In the case of weakness to poison snowflakes appear, I tested with feather (I feather shot the lich) and some bubbles floated around me when it was reflected. Different enchantments cause different visuals upon impact. Weakness to poison creates red rings around the enemy. Drains cause the enemy to turn red. Light causes a green spiral. Some (like dispel) seem to have no visual. With multiple enchantments on a bow (probably the same with a multi component-spell too) you can have some effects absorbed, some reflected, and some get through. And it seems like they can conflict the visuals because my bow has light, command creature, weakness to poison and weakness to magic, and I have had hits with no absorb or reflect visuals at all do no poison damage and others that do full damage, but none did partial damage expected if only the weakness to magic was inactivated. In the same tests I had the pink glow appear and also get full damage and no damage, but also partial damage.