I have a bride that wants SMBC. Can you get SMBC white? I have tried the wilton white food coloring (2 bottles) and it dosen't lighten it much.
How well does SMBC hold up on a hot day?
Unless you are using really yellow butter, then properly made IMBC and SMBC are very close to white. Anything made with butter isn't going to be a snow white, but for me, anyway, it's white enough. You can try adding a tiny bit of violet to counteract the yellow in the butter.