Max Contact system formatting is controlled by a CSS file. The CSS file is called 'contact.css'  Being a text file, it can be edited with a text editor.  All the tags are documented in the CSS file. Here is basically what it says within the CSS file:

The popuptitle tag is used as the text font for the words Email Contact Form

The titlebkgnd tag is the background of the box for the words Email Contact Form

The bodybkgnd tag is used for the main color of the whole Email Contact Form

The subheader tag is used for the words "Here's what you entered"

The content tag is the main body text format

The contentsm tag is used below the Send Email Message button to say "Have patience."

The error tag is used whenever an error in input is made, such as a bad email address, for example.

The thankyou page is used for the words Thank You after the visitor has pressed the Send Email Message button.