Spells: particle effect "upgrades"

[Tecmos Deception]

What I mean by upgrades is, when a level 1 casts minor shielding, the particle effects are green and only green. Later on, orange gets added in. Still later, blue gets added in.

On live, I recall the first "upgrade" to particle effects coming at 25, and the second at 50. I just made 39 with my enchanter on p99 though and am getting the red+orange+blue on shielding spells already.

Can't find anything about this in a quick google search, and it's not a big deal. I was just curious if anyone else remembered this like I did, or if my memory is just off.