I probably could've done a better job of explaining what you had to do, but I assumed you would be able to figure everything out eventually since (I'm assuming) you were using Disguise's Tileset Resource. Anyway, what I meant for you to do was to load your textured background image in TilesetPal, reduce colors (setting 32 indexes to "Available" and the rest "Don't Use"), and save the final. You could also load the rest of your palette before doing those steps, as long as you use the same settings. From there I recommend using PalSuite to adjust the palette so the textured background colors go from lightest to darkest, and then you can use TilesetPal (but NOT IrfanView or PalSuite) to load the complete palette back into the image. The final product (with some extra adjustments) should look something like this:



And its palette:



Also, the first index in your palette should be black to avoid potential problems.