Pav Bike Store Theme

Hi, is anyone else out there using this theme? I have a question about the 'Custom Module'.

I'd like to alter the 'Custom Module' background and font colours but, when I try and change the:
/*custom module*/
.warning_inline,.error,.success_inline{
background-color: transparent;
border: none;
padding: 0;
}
in the main stylesheet it doesn't change anything on the actual website. Is there anywhere else that I can change the Background colour and font colours for this module please?