Hello,
I've made my second ever tileset! Using photoshop, I've done the tileset, then saved it as 256 colours in paint. Yet when I get my tileset running, Jazz, along with the menu and status seem to be coloured red. What's going on here? Help would be much appreciated.

The tileset palette is also used to colour sprites. Open a normal jj2 tileset, put it in 8 bit mode, and take a screenshot with f12. Open up that screenshot and look at the palette. You'll see several gradients at the start of the palette. Take those and put them in the right position in your tileset, and the sprites will look the rigth colour.

Many thanks, the sprites look perfect now!