It would be nice to see that implemented to all skills. Exactly the same as Siphon Souls has, where it changes its color from purple-ish to green when upgraded via transmuter. The color of a particular PFX could change by every percent of the conversion, like, if we convert 45% of physical damage to fire, and we use Forcewave for example, the PFX would have red-ish colo, if we convert the damage to chaos - black-ish, cold - blue-ish etc. Also, to make sure people won’t be sad about that, add an option to the settings that enables/disables that feature.
It is known that not every skill, proc or damage type has a PFX, for example blitz has a little of “dust” coming from our character after we collide with someone, so maybe change that into fire (if converted to fire). Meteor shower’s physical damage would not be affected, as the physical part is the rock etc. Skills that do not have any PFXes could get something like little explosion of fire, ice, lightning, aether smoke, chaotic fire.
Also, I know that could be kind of hard to do, because what if we have physical damage converted to every other type? What if we convert to elemental? It could be fixed to apply either the highest percentage to it, so if our aether conversion is at 45%, and all others are below 45%, our skill is green - setting multiple colors at once would not work nicely, because it’d either be required to add more PFXes or mix the colors (like, 50% cold and 50% fire would give us, let’s say violet, and violet could be vitality, so we’d be mistaken we deal vitality damage) - mixing would look terrible. Talking about elemental, yeah, this one would be also hard to do, but you can always make it to change the color constantly, like, let’s say the PFX lasts 1.5 sec, so 0.5 sec would be fire, next 0.5 would be cold and then lightning (but it’d look kind of bad, so it’d be better to make it “float” a little better, like change it’s color from red to blue to white (lightning) 10 times over that 1.5 sec).
I hope to see such change in the game, it would really nicely affect the gameplay for some people.