These icons are a request by Sandro Andrade, the developer of Minuet. They are monochrome because of explicit request by Sandro. I will soon add them to the breeze-icons repo so you can quickly try them (they are used just by Minuet, so they will can't make issues for other apps in the meanwhile...).
They use the stylesheet, I tested it with Cuttlefish. Everything seems to work fine.

Please Andreas let me know if they are OK. Though they seem to be not vertically centred (by 1-2px), instead when they are all displayed in the same row they have the horizontal lines aligned, that seems important to me for a consistent look.