I think this is what I'd do.

I like the second from bottom with the narrow blue and wider green. I like that green better than the brighter green. How about the thin orange and that green in a wider border?

Blue inner border with outer border same as sashing. Might make the inner border a little wider.

Also I wonder what binding with that pink would look like Might clash too much with the orange or maybe not since it is in your main fabric too.

You gave lots of options and have gotten as many opinions! :D Good luck making your decision.

Orange inner with the blue outer border, very nice!

I like the sashing as inner border - it finishes the sashing then the green or blue for the outer border.

I really like option 3 it just feels right. Whatever you decide will be fabulous.

Yes, I agree.

Options 2 and 4 are the choices I like the least. I can't wait to see what you go with!