In my travels, I've found numerous magic items. These items have a color (so far only red, green, and blue). For example, the Thieves Guild armor (which can't be disenchanted for some reason) is green, items I've enchanted are blue, and some random items I've found are red.
Is there any meaning to these colors (maybe relative power level)? Has the Skyrim Creation Kit shed any light on this?
Nils Munch is mostly correct: each enchantment uses one of a number of shader effects (as they're called in the Creation Kit), but the Creation Kit does specify which shader goes with which enchantment.
Categorizing them by color, here's what I found:
From looking at this list, the colors are, for the most part, intuitive:
Of course, there are exceptions and liberties Bethesda took based on whatever aesthetic choice they decided to make.
There's also the case of items having multiple enchantments: the game chooses only one of the enchantments to display as the effect. However, it's not clear to me which one it chooses: I suspect it's either the first in the internal enchantment list or the last.
Every enchantment has a matching particle effect and reflection filter.
Also the enchantments you might not have access to.
Which colors and strengths that goes with which abilites is up to the Game Designers (Bethesda).
As far as i have understood this its related to the power which is enchanted on it. For example red on a weapon can mean bonus fire damage. Or blue bonus magika or cold damage.
every enchantment has its own color like fire=red-orange ice=white
