Very nice colors but I think the crop should be a bit tighter on the butterflies as they are the subject of the photo. The strong contrast between the blue sky and green foliage currently dominates the photo and the eye is drawn to it rather than the butterflies since they make up such a small proportion of the image.
Hey, I was thinking of going do National Bridges State Park in Santa Cruz and doing the same thing! Love the colors on this one. I have seen some tighter grouping of butterflies though, that may have come across better. The blue sky adds to this pic!