I was wondering what color flow is, and what it is used for?

It's basically thinned royal icing used to make plaques and decorations that need to dry hard. Outline a design in stiff RI, pipe in thinned RI in whatever color(s) & let dry.

I personally would say that it is in the same family of royal icing, but it is not actually royal icing. Colour Flow is more for decoration and instead of making it with meringue powder (like royal icing) you make it with colour flow powder. It dries hard just like royal icing, but it is supposed to dry shinier than royal icing would. I find colour flow to be smelly though, kind of a chemical smell, and I dont really like that.

I like it, but rarely use it. Mine always seem to take forever to dry completely.