Yea that happens when you save it as a GIF format. I don't know if there's any way to clear that. If you want to show the animation to everyone when it's done, you can record it just like I did.
1st. Save the sprites in BMP format as I said in PM 2nd. Record the animation in Pivot itself, don't try to record it from the GIF because you know when we convert the animation into GIF format, it's quality is usually bad.