The big yellow patch is what indicates that it is a male, while the female has only the brown spot on each wing. The feature photo is one typical view with a greenish/yellowish hew on the folded wings while the top of wings are usually a bright white like the photo below where the same butterfly is strangely contorted. See more of my photos of this interesting butterfly in my gallery: White Angled-Sulphur, Anteos clorinde. They are found as residents from Argentina to Mexico with migrants going into the Southwestern U.S. and Great Plains.
¡Pura Vida!