In reply to Tom.

I had a chance to go back and look at the show color palette button this morning. I do remember seeing that button now, but it wasn't apparent that it would show my theme colors. Plus, it's tucked in there right next to the clear color button, which shares the same design. I definitely think it would make for a better user experience to follow the core model of showing the palette by default while providing a button to add a custom color.