I think I know what you are talking about (tiny pieces of butter /shortning?) mine does that sometimes but when I leave it for a day they disappear & the color sets amazingly.
Have you tried leaving it on the counter a while to set ??
I never use merengue powder and also use wilton colours so i don't think that is necessary.
if you're getting lumps of shortening or butter, you need to ensure both are at room temp prior to creaming and cream it very very well. if you have a weak mixer, this may be the culprit.
Hi, This might not be the problem you are having but I thought I'd send the bit of info to you anyway. Some times the Wilton colors will not give you true colors unless you have milk in your icing. I only use water and sometimes I have to add a little milk say to get lilac otherwise no milk it will turn blue.
What color were the icing colors you used that had the spots?
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