I heard somewhere (I forget when/where x_x) that if you make a mod that only changes the graphics of units, it won't desync on battle.net. Is this (semi-)true?

It is true.

You'll need the other person to have the mod, though, so you can both see the changes. Either that or must have SCMloader on.

I meant if only one of the people had the mod running, >_>. I don't care about the other people .

Graphics-only mods work fine on bnet, but it'll only work for you, the other people will still see the normal graphics.

I always run DreamCraft and it works fine on bnet. Only problem is forgetting what color I am. :\

Yeah, I just wanted to know if I could play with the altered graphics without desyncing, it doesn't matter if the other people have the mod or not. I have an evil plan that involves a graphics-only mod...

.grp* only mods won't desync, among a few other things. If you change the graphics of something, you can't meddle with its iscript, its size, or other things like that.

You could also edit palettes, like the cloaked unit palette for instance

Ah, I hadn't thought of that... hehe...

Modifying iscript, DAT files, etc. will work on a conditional basis with people who don't have your mod.