AI have what might be a silly question, but every time I try to make light blue buttercream it ends up with a greenish tint. I assume this is due to the yellow of the margarine I use. I don't like the taste of buttercream with shortening only so I usually use half shortening, half margarine. Can anyone suggest a way to get a pretty, pastel/light blue-colored buttercream without reducing the amount of margarine? Thanks.

Ause white margarine which I've never seen available -- but just as an aside my mom told me that at one time margarine did not only come in white they also included a packet of yellow color to mix in yourself -- trivia for the day :)

but back to your issue -- yes you can't get soft blue nor soft pink you get green and peach respectively -- so i avoided taking orders for cake iced in these colors -- if the client insisted i'd explain they'd get an all shortening icing -- if it's just to do decor i just made the blue or pink separately

AAnother option if you'd like to experiment and are set on getting the blue color would be to try other shortening-based butter creams. Maybe you would like the taste of a different recipe? Here are two that a lot of Cake Central members swear by.

[URL]http://www.cakecentral.com/a/sugarshacks-buttercream-for-a-6qt-mixer[/URL]

[URL]http://www.cakecentral.com/a/indydebis-crisco-based-buttercream-icing[/URL]

If you drop a teensy bit of violet in your buttercream before you put the blue in, it will take the yellow out.  It completely boggles my little mind.  That said, it's still a song and dance, depending the exact color blue you want.  But you can avoid the green this way, for the most part.

Adding a bit of violet worked perfectly!!  Thanks!