hold on a minute, if you just wanna rip from ZSNES shots all you need to do is change the video mode to an 8bit one. I recommend 640x480x8 VESA2, this one always gives you pictures with the right (rom) pallete and they are fully rippable in ZQ.

If you really wanna go the hard way and use a paint program to reduce colors, use XaraX, but I really suggest you don't go that way, since every shot will have a divirent pallete