Quote Originally Posted by tilt View Post
I don't use Gimp, but if I had the first plasma image in photoshop and wanted to use it as a sea - I'd desaturate it and then change the hue (coloring) it to blue after. Don't know if you can do that in Gimp however...
In one step with the colourize filter (It desaturates first). More control if you use the channel mixer.

-Rob A>