Fix unclear text in broadcast message view.
What does this MR do?
Fix weird text instructions on the broadcast message page.
Why was this MR needed?
The existing text was extremely confusing. It read: "Hex values as 3 double digit numbers, starting with a # sign." Hex colors are not always "digits" and saying "3 double digit numbers" is extremely confusing. Just change this to say "6 character hex values starting with a # sign."