I'm new to Affinity, trying to unlearn 30 years of Photoshop habits, so please bear with me....
I want to recolor an antialiased icon, currently black, to some other color, color X. The icon is alone on a layer, so the surrounding pixels are transparent. The 100% opaque black pixels to be 100% opaque color X, and each of the antialiasing pixels that are n% transparent black to become n% transparent color X.
In Photoshop, I would typically make a quick selection marquee around the whole icon, and use Cmd-Up, Cmd-Dn to nudge the image and quickly "lift" the icon pixels into a selection. Then I would recolor those to the desired transparencies described above by using Cmd-Del or Cmd-Shift-Del depending on whether I wanted to change it to the current foreground or background colors. (Operating from memory on those keystrokes; it's been a while and I don't have PS to pull them from muscle memory, but if I'm off, hopefully you know the ones I mean.)
What method would I use in Affinity Photo to accomplish the same thing? Thanks!
(BTW - I tried Fill with Primary Color, but it turned all the antialiasing, n% transparent pixels, solid. So maybe I'm just missing whatever step it takes to get the pixels "lifted" into a selection the way nudging does in Photoshop, and then Fill with Primary Color would fill appropriately?)