In Mail footer, how do I add highlighting to the text?

Hello Pranayama20,

Thanks for visiting Apple Support Communities. We understand that you're wanting to add colors to your Mail signature. You're able to create plain text signatures using these guides:

Change Signatures preferences in Mail on Mac

Create and use email signatures in Mail on Mac

Thanks again, and take care.

In order to do this open a blank email and format your signature / footer you want in every email they way you want it with highlights and special formatted text.

Then go to preferences and click on signatures. Uncheck the box at the bottom that says "always match my default font". (see screenshot) Then copy and paste in the signature with formatting you created in the blank email and the formatting should copy over.

If you want this in your mobile signatures in your iPhone send yourself an email with the signature then copy and paste it into the signature settings in the iPhone and it will copy the formatting that you sent to yourself in the email.

Hope this helps!