Thanks everyone. FatCat, it’s not really difficult. I’ll tell you the most difficult part would be not having enough tips and bags and having to wash and reuse all the time. Just start with the first color (the darkest) then keep adding more white to lighten.
Heather, my cream cheese icing doesn’t have any other liquid except for a bit of clear vanilla extract. It was actually a little too stiff for my liking so I thinned with a few drops of water. To smooth, I usually use a hot, wet spatula and it works.