I have uploaded to my Dropbox Ambiant Mate different color themes and icons for mate desktop. These work in Trisquel too, as seen below in screenshots.
Icons
That was one of the things that put me off of Ubuntu Mate was just too much green, but now a whole host of colors, which were originally from 20.04 but work in any Mate environment now. So download link to my Dropbox is below for you to download and install.
Before I forget I got Nemo running in Trisquel as default.
