I was changing the message box box to be more attractive, but the font color was set to a light shade and couldn't be changed. I commented out this line in the base css file for the facebook go dark them.
body.htmlarea_styles {
color: rgb(202, 210, 216) !important;
}
To comment out a line off css I found that you surround it with /*css*/
After that I was able to use a lighter background, and the darker font. If I change to a darker background, all I will have to do is remove where I commented it out, and possibly change the color there.