I'm not too sure what else to add but I think it would make sense if planters were dyeable. You can dye hardened clay (terracotta) but you can't dye planters.

And I guess that brings me to the second part of the feature request, if planters were made dyeable it would make sense to make flowerpots dyeable as well (although that may be out of the scope of what the mod achieves).

I guess the biggest motivator to this feature request is due to the fact that the planter's colour doesn't always match the colour scheme of what I'm building.

I might make an add-on for all these things. I really don't like block variants when added like that instead I try to always add unique blocks