¿Puedo cambiar el aspecto de mi página de pago de PayPal a través de MemberMouse?

No. MemberMouse no hará nada para cambiar el aspecto de su página de destino de PayPal.  

Dicho esto, hay que señalar dos cosas:

1. The PayPal account you have can influence the checkout page used on PayPal. As it’s a PayPal feature, we are not clear on how this works but we can say that older PayPal accounts will use different pages than new ones.

2. PayPal processes one-time payments differently than subscriptions. One-time purchases will go to a checkout page on PayPal that’s significantly different than the one for subscriptions. The reason is that with a subscription, a PayPal account is required; with a one-time purchase, it’s not. You can attempt to purchase a one-time purchase product and see the difference.