This page allows you to customize the PayPal Order page with several different options.
With the first option, you can have named page styles within your paypal account. If you have this you can type the name here. You can also choose to use your default page style
Otherwise you can setup a different page for each button with the rest of the options
A url for an image puts a banner at the top of the page. It should be hosted on a https url. Or else there will be security warnings if PayPal does't refuse the image outright.
Then you can select different colors on the page. From the color behind the image, to the background of your order page and finally the border color.