save for web settings in photoshop cs

[pixelrox]

Could someone post the best lossless settings for the save for web dialog box in Photoshop CS?

For gif and for png.

Also, when changing colors from 256 to 32 in gif settings, the colors disappear from the color table. Does this alter the original colors I chose? In the original 256 color selection I have 7 colors including black and white in the color table. I am learning to setup my color swatch for now. Help appreciated.

[Mathias]

The best lossless settings? It will always depend on the image at hand. You need to optimize with your image in mind. There's no best.

For GIF and PNG? Indexed color mode is indexed color mode. Format doesn't matter. PNG supports full-color too, but that's not of concern here.

Of course colors disappear when you go from 256 to 32. You just nixed 224 colors. The image no longer uses them. Yes, it affects the image, altering colors. You can also convert to indexed mode by going to Image > Mode > Indexed Color.