No Support for PNGs with Palettes

[Peardian]

Texture Remix will fail to load any PNG that uses indexed palettes. There should be a way to check of the loaded image uses an indexed palette and, if so, translate the palette into RGB(A) when loading the pixels.

[craftyfirefox]

You could use
if( image.getType() == BufferedImage.TYPE_BYTE_INDEXED )
to check for 8 bit paletted, then use
int[] argbvals = image.getRGB( 0, 0, getWidth(), getHeight(), null, 0, getWidth() );
to retrieve the values in "real" format. Might be a lot slower than directly accessing the databuffer as you do now, but has the great advantage of "not having to take care for anything else". BTW, since you only load those pixels once, using the getRGB-Method for all your needs might be a way to go anyways.