How to save gif and png correclty?

HI guys,

I need your help. I/m new in photoshop, I opened an image file and remove the background of an image. I will use the image in Flash so I need the image to be in transparent background. I saved the PSD in gif file and png file, but the color was not as clear as the psd. Can you please help me on how to save an image in gif or in png correctly. Because when i save it, it ask some questions.

need your reply.

thanks so much