Where's my Prismatic Frog?

[Omukinha]

Since the 1.6 mobile release update (I'm from PC), I noticed that my prismatic frog egg has disappeared and instead it there was a green frog egg. I thought that I accidentally have lost my old egg, but then I noticed that many of my other frogs that were in a fish tank are also green, and they used to have other colors, such as yellow, null... Only the red frog in the fish tank wasn't affected.