Formula does not work on none .PMP files

Win 7
PMNG ver. 7.2.7

To recreate case:

  1. Open PNG file
  2. Enable formula mode
  3. Choose Morintaris’ color replacer formula
  4. Replace chosen color from the bg color to the fg color

The formula works when working with a PMP file, but not anymore when with at least a PNG file.

Demo with a .PMP file and a .PNG file:

I have the same problem but mine is worse. I can’t get Morintari’s color replacer working in PMNG 727.0 at all! and could really use the tool!
Thanks in advance,

Is this not because of the alpha channel that’s active on a PNG? It’s possible the color is being replaced but the alpha is not.