Thanks for this great tool. I had to make a color transparent in my wife's logo. On her iMac the pre-installed tool "paints" asked for an upgrade as the logo is bigger than 800px in width. Thanks to paint.net and your great tool it was an effort of 5 minutes (including donwload of everything) on my windows 10 computer.
I copied your DLL into the effects sub-folder of paint.net and after a restart of paint.net the actual change was done in a minute.