Terrain mask madness

[Moonpaw12]

I know how to make them and have flattened it, made it 513x513 its in RGB mode and tried saving it through three different programs and all as .png but every time I try to load them no matter what I put in it looks like big stripes? I can change the colour of the alternate stripes but then the opposing ones are black? and if I change the other colours for the mask it kind of changes the coloured stripe in tone like its underneath it? Help please I'm really confused.

Moon x

[Ruby1234]

If you haven't done the copy it, then create from clipboard, then flatten trick in GIMP, I'd do that, but then perhaps crop it to 512x512 and see if it'll work.
For some people that size seems to work better.

[Moonpaw12]

Thank you I'll give that a go now

[Moonpaw12]

Problem still not solved :/ Please help