I would not be able to decide this without laying it out and comparing. I agree that framing it might be good, but on the other hand introducing another shade might overpower such a small piece. Lay the piece over the border fabric folded so it sticks out narrowly along a couple of the sides, and then stand back and have a look before you sew it on. It might help to look at it through a peephole, available at home centers for checking who is at the door. It has the effect of letting you see the overall effect. Or lay it out and take pictures, and then study them side by side. One is sure to grab you more than the other. I doubt it will be white, but wouldn't bet. How about a striped fabric with all those shades on the bias? Er, maybe? It will be a lovely gift whatever you decide.