As I understood about this code, on background line you should replace this value with the color you want.
either hex value or rgba one.
Not sure why it's not showing on the post but that's what I'm talking about.
. ipsMessage_sucess {
background : #32a84 ;
}
or
. ipsMessage_sucess {
background : rgba (50, 168, 78 );
}
Colours are just an example.