Is there a way to type in color on a Mac? Or is there an app that can do this?
For example, if I'm typing in a document or an email, I'd like to change the color.
In a Mail? Sure.
Those fields that support it (in native OS X apps like Pages, TextEdit, Numbers, etc.), will often map Cmd-Shift-C to the color picker window.
More generally, any app implementing
Anywhere else, like "normal" text-only boxes, there's no such feature I know of, and it's unlikely you could just change the color there on the fly, because after all, they're just supposed to contain text. It is certainly possible to write applications with changeable color text fields, but I haven't seen one that actually lets you do that "live".