CSS override

Hey guys,
I have a problem. I want to change size of the price (see privat link).

p.product_price.price.headerfont {
    color: red;
}

Would work, but the get override by enfold. I would need to change CSS on

#top .main_color .price, .{
 color: red;
}

To get it worked. But with this code, I would change price style on all sites, not only on single product. Can you guys explain me, how I can fix that?

Best regards
Alex