Looks simple, but can't work out transparency. [Solved]

[Dazz]

Hey guys,

so I've got a game here I'm trying to rip that looks super easy, but the big pieces of art seem to be giving me some grief.



As you can see, I can get them working just fine in tiledGGD, but the outline disappears with transparency enabled. When disabled, it looks like this:



As you can see, there's a bunch of weird colors going on in these spots... And I have no clue what to do to fix this. Here is the file these came from specifically:
https://dl.dropboxusercontent.com/u/26973982/rom02.bin


If anyone has any clue, I'd appreciate it:

4x4 Tiled, 16 BPP, Little Endian
Palette is RGB.

Thanks!

[Garamonde]

I'm quite fond of that art...

[Deathbringer]

Are you sure there should be an outline in the game?

[Dazz]

Yeah, I'm pretty sure - looking in game, there's quite a clear outline going on. Regardless - you wouldn't suspect all of those pixels to be transparent if they were different colors to the background, right?

[Dazz]

All good, Barubary worked it out. It's all a bit weird, basically. He built a tool to convert the files from 16bpp to 32bpp, as it was something to do with that jargon. He's a super genius.