Fitdream, if you want to use PayPal Website Payments Pro to accept card-based direct payments and add the separate checkout button for that in your cart, you would need to upgrade your PayPal account to Pro and also follow our integration instructions to make proper use of that service level, as explained here:
Hulby, the cart with grey table-cell backgrounds would be our standard cart appearance; your site's WordPress theme is overriding that. Unfortunately, sorting that out is not nearly as simple as what you've described trying already. The problem really requires in-depth working experience with CSS/HTML coding and Web page layout structure, and the tips on the help page I linked are intended to point someone with that knowledge towards looking in the right places to apply their expertise.
If you're not experienced enough in Web design to be capable of, say, writing your own WordPress theme in raw code from scratch (not that such is necessary here, just indicating the level of expertise required), the easiest thing you could do would probably be simply applying different WordPress themes to your site until you find one that doesn't override our cart's standard appearance. If you'd like some help trying to sort it out with your site's current theme, we can recommend the competent, E-junkie-experienced developers listed in our directory here: