Maybe it's doing some kind of dithering there? The color issue could be a problem of Windows/Mac. I can't tell. I was just referring to the 16-bit discussion coming up. PNGs can't have 16 bit in Toolbag at the moment and the TGA loader is also working to correctly in toolbags current version and can't have 16 bit, either.…
People say PNG was notorious for alpha issues with Photoshop, the problems should be clear now but give TGA a go, I think Earthquake mentioned something about Marmoset and PNG's not too long ago but I forget what that is haha. With TGA's I always usually leave premultiplied alpha on and since you're using an alpha, go 32…