Transperancy Effect, Need Help!

Ok, my problem, I can't seem to get a basic transperancy effect going. What I want, is to give some units the look of invisibility, but I don't want them to actually be invisible, basically I want them to look like ghosts.

So far I've tried adding special effects with triggers and as a passive ability, neither seem to work, however the problem is probably that I've done bad triggers.

I won't post any of what I've done, there's no real point since I can't get anywhere with them to work as a base. All I need is a passive look which won't consume too much bandwidth across a b.net game.

Animation - Change Unit Tint (or something like that, search the animation triggers)

Absolutely brilliant, thankyou so much.