it was VERY stressful, but after much stressing and giving up several times, i FINALLY figured out how to more or less do smegma with the methods in the screenshot of the editor teaching me how to edit i posted >>11344389. things i learned (in gimp btw):
-you can actually save selections (select > save to channel)
-you can change the color of "plasma noise" under "colors" > "colorize" (not understanding how to do this on the "plasma noise" window itself stressed me out so much and made me give up several times)
-the mini black/white boxes bottom left of the active foreground/background color boxes under your tools resets your foreground/background color to white/black (in case you're paranoid about your black/white being off, which i was for every caption until now)
-the bottom left corner of the canvas is the "quick mask" button
-to evade the brushes recommended in the editor instructions screenshot i posted from making the smegma entirely see-through, you can use them to select from a smegma-colored layer, as i did in my picrel here (not understanding this also stressed me out a lot

i was about to try drawing the smegma myself (giga stressing me out) when i realized i could do pic related instead. pic related is just a proof of concept; i'll hopefully be able to actually make it look good if i tried and added shadows and potentially a darker "stroke" (outline) and stuff