In order to be able to change your font color, size, add attachments, etc in MSN groups with Mozilla Firefox---you will need to install 2 add-ons from Mozilla, you can find them at the links below:
After they have installed and you have restarted Firefox...go to your group. Right click in your groups page and click on "View Page in IE Tab". This will make the page look like it would in IE. When you click to start a new message or reply to a message, you will see your font and other options.
NOTE: If you have 'tabs' enabled in Firefox, you will not get the normal pop up for the message reply.....the reply box will open in a Tab, but it will still have the normal posting options.
If you do not like your reply box opening in tabs...then instead of right clicking inside the group and hitting view page in ie...right click in the message box and hit 'view page in ie tab'...this will make only the reply box pop-up view in IE mode.
~Tips by BamaVamp~