[Plugin: WP-Table Reloaded] Head Row Color

Hello,

I am using this in my custom CSS:

.wp-table-reloaded-id-21 th {
color: #ffffff!important;
}

and am adding a new custom css for every table. Can i have just one that covers every table? If so how would I enter that in the CSS?

Thanks

http://wordpress.org/extend/plugins/wp-table-reloaded/