Those textured background tiles burn my eyes. It's a shame to still see people having palette issues.

What I would suggest is:

• Read about palettes from Disguise's Tileset Resource (DTR).
• Get an image before you reduce any colors.
• Open TilesetPal.
• Learn how to use the basic features of TilesetPal.
• Load your tileset image in TilesetPal.
• Use the Palette Merger feature to load the tileset palette that goes with the textured background tiles you're using (I can't say for sure that the Diamondus and Carrotus tilesets use different palettes for the textured background, but I can't check right now and they are probably different anyway).
• In the Palette section on the main part of TilesetPal:
  • Change the top row (Index 0-15) to Don't Use.
  • Change the sprite colors (Index 16-95) to Don't Change.
  • Change the textured background colors (Index 176-207) to Don't Change.
• Reduce colors.
• Save final.

If my directions made sense and you managed to do all that, the textured background won't look horrendous anymore. By the way, this method doesn't account for palette events since that would complicate things.

And so much for a reply to the first mentioned problem. I personally think this other problem is much more important.