Set FrontPage to use Hex instead of RGB in css

[Newbie Supreme]

When making a new style sheet (css), FrontPage uses the rgb syntax to set
colors for fonts, hr's, borders, etc. Is there any way to have it default
to using hex values instead? I see no options for this in any of the site
settings, page options, etc.

I have read that there's no difference to browsers, but since all of the
other non-css settings for color seem to be hex values, and all of my sites
to this point use hex values, I would like to keep it consistent.

Thanks for reading, and for any help on this.