I hate to double post, but I need help with something. I tried masking the tileset I'm working on but no matter what color I choose the JCS program just refuses to make it possible to walk on most of the tileset.

I uploaded a ZIP file with both images I tried using on my website host, click here to see it.

Anyway, I tried every color I could find, and not one of them worked, not one. It was all ignored, and the masks are completely empty. Can someone help me out with this?

I know this might look like a lackluster titleset, but I'm only using it for the first level, and I assure you that will be the only short level, the rest of them should take 5 minutes at least to beat.