You're almost there. Some words of wisdom if you're using Photoshop CS6:
-For Stitches = Try saving them as .png > .jpg -For Gifs = Try saving them as "Adaptive," its right next to the colors menu when saving Gifs. (Helps with keeping the color from looking saturated.)
As long as the site doesn't re-encode uploaded PNGs, then one could always be cutting edge and try animated PNGs instead of GIFs in order to preserve the color palette.
(though, as one would expect, 24bit-color animations will be larger in file size than 8bit-color animations)