Hello, here am i with a problem with colored big maps again...
Since i read this (http://worms2d.info/Colour_map#Adobe_Photoshop), i had no problems with creating maps, but the last one i created, got some bug with the background. When editing the map, i made a single black blackground (the path that turns into transparent, and where worms can move), and saved the file following all the instructions of that link above (64 colors, etc), but when imported to the game, the map showed with some black squares and stains in the middle of the black background that should turn into empty path, and that squares and stains are solid, the are not only a background glitch, so the map turns impossible to play. How can i solve this? Maybe theres something i must do on photoshop before saving or what?

The squares etc. you see are probably JPEG compression artifacts - if you copied any JPEG images or saved your map as JPEG at some point, such artifacts will appear. They are areas which are nearly but not completely black, and the game treats them as such instead of transparent. You can remove them using the wand/quick select/fill bucket tools (set a non-zero tolerance until they select/fill all areas that should be transparent).

Thanks for the answer man, but i figured it out just after posting the question :P
Yes, its just like you said, i was forgetting about the rgb=3 and 4 colors. They are almost black, but not totally, i just removed them before saving the map, and it worked. Thanks anyway :D