@Carmelo_DrRaw Thanks for the tutorial. Edit: I rewrote this post to make it more useful. I also apologize for using a development release, which might cause the XCF file to be incompatible with your setup.
Here is the XCF file for GIMP users to follow: DeepBlueSkyEffect-2.zip (8.2 MB). Let me know if I made any mistakes, or if you have any questions. Clarifications:
- G+B+R comes from New from Visible with only Grey, I: Blue and I: Red layers visible.
- Modify the Opacity of layers Blend (overlay) and G+B+R to change the strength of the effect.
Original Image
Deep Blue Sky
Layer details (Blend mode)
GIMP Version