Please see the screenshot beneath. I'm using Adobe Acrobat Pro DC Version 2019.010.20064.
I'm trying to convert the book's default (C, M, Y, K) = (99%, 98%, 18%, 6%) (ie dark purple) to (90, 0, 90, 0) (green). After I click 'OK' and click 'Fix', Adobe Acrobat executes the fixup, but the color fails to change.