Green Sea... and Green Cloud?

Warm weather is a normal condition in the brazilian northeastern coast. Yellow or gold sand, too. The colour of the sea varies from green to blue, sometimes brown, if there is a river close. The sky is of a deep blue. Today, in Maceió, the sea was in emerald green tone. If one takes a look in the clouds in the upper middle part of the picture, will see a green tone also. An optical reflection? I don't know, it was amazing...