Too many complementary pairs here to demonstrate the effect of one colour contrasted against its opposite. If you could have shot the blue butterfly against the yellow flower and then cropped tightly to eliminate any red or green, or else if you had shot just the red and green flowers, you would have had a better demonstration of complementary colour contrast.
TOOOOOOOO Small why do people do this? 640x480 works great useing "save for the web" in Photoshop. My screen is 1280x960 you how small this image is on my screen? I didn't even see the butterfly till now. Bigger is better just not bigger then 640.