how do I change the font color in the subject box of a message?

[Guest]

My default font is black on a white background within the subject box of each
email message I create. I'd like to be able to change this to red or blue for
some more important messages rather than just use the importance icon which
sometimes tends to be ignored.

 

[Vince Averello [MVP-Outlook]]

You can't, the subject field is plain text.