Normally, I prefer blue above all others, no matter what, so the fact that I think yellow is the better choice means this is without bias (forgive the quilting pun, there - ha!). I think the yellow (#2) makes the blocks pop out and become eye catching, whereas the blue (#1) causes the colors of the blocks to become toned down and more quiet. Didn't know quilt blocks had so much personality, did you? :)