(wewt! first post!)

So recently I've downloaded a few mods to see if any old ones were compatible with the new build, upon noticing that one of them didn't have a ModuleIcon, I decided to make my own. It looks fine and I stuck to the game's pallet (to my knowledge), but in-game it's dark gray and transparent. Anyone know why this happens or how to fix it? Probably something stupid on my end.

Your .bmp file has a colour table which you cannot see directly. It's like a map that programs use to discover what colour is what.

Some paint programs are notorious for messing up this colour table, Windows 7's paint for example.
You won't see directly that the colour table is messed up, but it probably is.
Advanced programs like Adobe Photoshop or perhaps GIMP (free! I recommend it.) can show you a .bmp's colour table.


So, err, how does all this help?

I'd recommend using GIMP to create your module icons. You should be safe then.