I recently picked up Kaleiki's Lost Training Staff from the AH, and tossed Enchant Weapon - Colossus on it. To my dismay, I saw no enchant graphics at all afterwards.

I performed the usual routine, change graphic settings (dropped from ultra), /reload, log out/back in, and deleted my Cache/Interface/WTF folders, all to no avail.

I then tried to transmog the staff into a cheap green staff I picked up from AH (for 1g) and instantly the teal electrics began coursing through the tip. I removed the transmog, and the particle effect immediately ceased.

I couldn't find any mention of this being normal anywhere, and the staff has no standard particle effect (that I can detect) to override the enchant graphic.