I am looking for a web-based JavaScript <textarea> editor with support for standard features like selectable font, text colour, paragraph alignment etc. However, there is one considerable constraint: Formatting should always apply to all the text, not parts of the text. That is, the user is able to colour all of his text red, or all of his text blue, but he shouldn't be allowed to mix and match.
None of the editors I've looked at so far explicitly supported this feature, short of hacking it into the editor. Is any editor out there able to do this out of the box, or with small amounts of configuration?
Thanks a lot for any hints!