Great idea! The workaround I’ve used has been to use the eyedropper to create custom colors by pasting an image into Miro which has the colors I want. Those custom colors are then added to your palette across all boards (see below):
I just posted this same thought, going beyond the add color / dot matrix organization method. I better organized my thoughts at the link below, including a mock-up:
@Kiron Bondale I’ve done that too, it’a decent workaround. The annoying thing is that your custom colours are placed at the bottom, although they are the ones you’re most likely to use. Not great from a UX perspective.