Pinned colors live in this browser. Download .md takes them out as a readable list, → Notes drops that same list in as a new note, and Copy puts it on the clipboard. Under Settings → On this device they travel with everything else: Save to folder writes them to Colors/pins.md and Load brings them back.
Read a color in hex, RGB, HSB and CMY, edit it with sliders in whichever format you like, and pin the ones worth keeping.