Angry Ponies issue

[Soobel 488]

Hi

 

I try to repaint Angry Birds image file, but... If i replace there some sprite (all the animation frames are on big PNG pictures, where program cut them for show in game) then happen something with colors and transparency:

 

Original yellow birds are cropped from the same image with Rarity and have no defects. Something with palettes? How to fix it in Photoshop?
(Earlier in Lucasarts Outlaws was same problems, there was needed right palette to load on image. But there was 256 color bmp files, 16-bit images have not palettes)