These work great with clever stackable magnet design system! It's very impressive.
If I had to nit-pick: I wish the blue were a tiiiny bit lighter to help the black really pop on it, and something feels a bit off with how the black printed on the red. It doesn't seem as true black as the others. The yellow, Green, and Black with white look amazing, perfect! I don't have the pink but from what I've seen online it's also perfect.
That said, really highly recommend, it's fun to match your aspect thematically at the table.