As with prior recolors, I used ImageMagick to swap specific colors for others:
This works rather nicely, except that the new PNGs need to be put back into Indexed Color via GIMP.magick convert 895_fire_field_%02d.png[0-15] -fill #14a400 -opaque #dc1428 -fill #1cc000 -opaque #e06c00 -fill #28dc00 -opaque #fc7c00 -fill #38fc00 -opaque #ecc828 -fill #50fc28 -opaque #ecd050 -fill #6cfc54 -opaque #fcac5c -fill #8cfc80 -opaque #f0dc78 -fill #b0fcac -opaque #f4e4a4 -fill #d8fcd8 -opaque #f8f0cc -fill #28dc00 -opaque #5c5cfc -fill #1cc000 -opaque #fc9c3c -fill #14a400 -opaque #fc8c1c -define png:preserve-colormap=true green_flame_%02d.png[0-15
But somewhere along the way, the multiple "white" colors of #fcfcfc seem to cause a problem. There are four of these used in the palette, so the imported frames seem to be stuck on the first one. There are two for "magic blue" and "magic red" as well as a yellow-tinted transparency that I want to use.
I've tried tinkering with the palette prior to exporting the images from GIMP, but I can't seem to find the right way to do this. How do I keep the proper transparency?