Thanks for the feedback! I plan to offer some alternative themes. I chose to spend my time making custom color support robust. For instance, there's dynamic code that determines which label colors have highest contrast on buttons depending on the theme color. So, there's some abstracted complexity there.

While the Postcard marketing page looks a little tailwind-y, I hope that the individual homepages look more polished and distinct. I've been working with a designer to tune everything, and I'll continue to make improvements.