red-eye-green-tree-frog-playa-nicueza-8.jpg looks like A. callidryas to me. Those found on the Pacific side of Costa Rica (which if this was taken in Playa nicueza this frog will be from I believe) tend to be much less colorful than those on the Caribbean side and can lack the bright orange and blue. From the photo I can make out some feint blue colouration and the vertical cream/white bars along the flank which makes me think this is A. callidryas.