Shoutbox

Yes that is possible, the style, colors, etc are defined in
"Events Style Sheet.xsl" which you'll find in your log directory.

Edit this XML stylesheet to your likings.
Example of how to do it can be found inside the stylesheet itself by looking at how the 'current user' is colored yellow (see the <xsl:template name="ContactBlock"> block).


PS: please cover the email addresses of other people in screenshots. Never ever put such mails in public.