I like the idea of a thin white border. It won’t even look like a border, it’ll just make the rest of the quilt float.
Then, I’d choose your favourite colour from the blocks, and make a slightly thicker border in a mid range of that colour. I’d bind it in a really dark of the same.
Luckily, there’s no quilt police to come and take you away, so you can try any/all of the suggestions here, and decide what YOU like!!!!