I think your butterflies are wonderful. Since I am used to seeing butterflies during the spring and summer, I would choose the light green thin border to represent the stems of the flowers the butterflies love so much. After that I would select a lighter blue for the springtime sky. The brown border in the second picture looks like autumn to me, and the blue of your first picture and the black in your second one seem too much like storm clouds. Is that too much of "waxing poetic" to make sense?