I'm a crisco only icing maker.
Sounds like you are not beating your fat long enough. Beating the fat breaks it up into teeny tiny particles. If you are seeing large pcs in your icing bag, it's not broken up well enough.
I blend the crisco, milk, vanilla and dream whip together, first. Then add about 1/2 cup of sugar to bind it all together. After that beats a few seconds, then I proceed to add the rest of my sugar.
What is your ratio of fat to sugar? Is your icing thin or watery, causing the color to separate? are you beating the icing long enough to really blend the color? The only time I've seen color separate is when I've had leftover icing for a few days, and even then, I just beat it with a spoon to re-blend it and it's fine.
I've never used merinque powder in my icing. no reason ... just never had a need to. So I don't think this is the reason.
I had this problem the last time I made any buttercream. I followed the Wilton recipe with 1/2 butter and 1/2 shortening (crisco). I tried to make this beautiful teal shade and it looked tie dyed... it was horrible. I also have "hot hands" and my icing ends up melting and looking horrible as I pipe it.
I haven't made any more buttercream since then, but the next time I try it, I'm NOT using Crisco.
I asked the same question and never got any real answers, so I'm not really sure what causes the problem. I also used the wilton paste colors.
Indydebi alluded to something that erinalicia also mentioned but...are you using the new, transfat free crisco?? If so, that might be your culprit... There are lots of posts here about the effect this new crisco has on your icing, and Debi has a great recipe here using dream whip that might just put a stop to your troubles...
Other than that all I can say is I just tried a bc icing the other day (all butter mind you) and it separated too, like nobody's business. Turned out I did not have enough powdered sugar in it and adding more miraculously fixed it.
Still, my hunch is it's the crisco...
Thanks again ya'll for all the tips.It's not the Crisco,because I use the Wal Mart brand shortening.Your description was right on about the tye dye!That's exactly how it looks! My hands are hot and I use the disposable bags,maybe thats part of the problem.
I have had this happen with dark colors. You could try to add a little corn starch in it to see if that helps.
Since I discovered Sam's Club icing and bought 28 pounds of it...
I am now problem free with dealing with Buttercream problems..
The texture is perfect and it takes colors so well.. I just whipp it and add flavoring to cover up the commercial taste. It is typically sweet, which most icings are. But the wedding I did last week, it was a big hit.. 
Hopefully everyone else's suggestions helped. Good luck! Quote by @%username% on %date%
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