Custom font size and colour in email body

I have an email submit button on my form, I  have auto filled the subject line and body of the email, I was wondering if there is a way to change the font size/ color of the text in the email body? Here is my current script:

this.mailDoc({cTo: "Email Address", cSubject: this.getField("Text Field").valueAsString, cMsg: "Email body text "})