I don't get it... I specifically did NOT put stupid salt in the buttercream because I didn't want to get stupid white dots all over my pretty pink cake.... only to get WHITE DOTS ALL OVER THE CAKE! I might try to cover them with dots of white buttercream but this sucks. Any idea what could have ALSO caused this?!?!?!

Are the dots clumps of powdered sugar? I never sift my sugar but I have read many recommendations for it on here.

It can be clumps of powder sugar or crisco. It could also be your water. This usually only happens with pink and purple for some reason.

Try bottled water to see if it helps. If not, make those colors ahead of time. Once they spot like that you can mix them in and then use it.

Are you using butter in your buttercream? If you are, these white dots could mean that you haven't whipped it for long enough. When I still see white dots in my icing, I whip the heck out of it and they will usually disappear.

It could be shortening if you use it in your BC recipe. Sometimes the shortening is not blended well and will spot the icing. I always blend my butter and shortening for a long time on low or stir on KA. For about 10-12 min. at least before I add any other ingredients. And at the end (after adding all ingredients) I blend it for about 7-10 min.
Hope that helps!

Hmmm, they aren't clumps of powdered sugar, I don't use real butter in my recipe... The stuff looked fine when I made it then the next day it looked like my cake had a case of white chicken pox. It looked exactly the way it does if you put salt in it and don't let it dissolve.

Yeah, I have no idea. But yeah- my purple had dots too... just like TexasSugar said,

I don't have an answer but know how you feel. I've been making icing with the same recipe and ingredients for 20 years and all of a sudden my buttercreme is gritty and I've tried everything...nothing works. I made a red tractor cake a few weeks ago and after a while went back to look at it and it was red and white spotted ! i made a batch of icing this morning and it feels gritty and you could almost pour it . It could be the humidity here...it's 103 ! I'm going to put it back in my mixer and add more conf. sugar to see if that works. I'm about at the end of my rope !

There are a whole list of things you could try.........since I don't know your exact recipe, I will just throw some things out there.........
1)Powdered sugar, if you didn't sift and make sure you are using powdered sugar that is pure cane sugar and contains no beet sugar.......
2)Butter, if it is too cold when whipped won't blend well..........
3)Shortening..........new crisco can cause some issues, and some store brands don't blend as well...........I have found that the Food Club brand is as good as the old Crisco........
4)Use milk for a liquid rather than water.........it will blend better with the shortening.....
HTH........