Open a canveas in Animation Shop and draw any thing on it.  We need something on the canvas to be able to go thru the steps to check the settings.

 

File...Optimization Wizard

Window 1....check Animated GIF file and check create a new animation from optimized animation....next

Window 2...Customize button...colors tab..check optimized median cut and check error diffusion....optimization NOTHING CHECKED...partial transparency tab....check convert pixels less then ...enter 40 and check yes...blend with and enter white.  This one can change and it depends on what you're doing as to what color you want you colors to blend with.  For the most part you'll want it to be white.

click ok

 

Window 3...next

Window 4...next

Window 5..next

Window 6..finish

then delete the graphic you used and you're done.

 

Be sure to check these settings once in a while because for some mysterious reason they do tend to change.