Hi,
1. The fact that the add to cart buttons don't look the same comes from your template CSS which is not correct.
It has the code:
div.hikashop_inserted_product_1 a {
padding: 15px;
font-weight: bold;
vertical-align: middle;
text-align: center;
cursor: pointer;
border: 1px solid transparent;
border-radius: 3px;
color: #ffffff !important;
background-color: #2071bc !important;
font-size: 13px !important;
line-height: 22px !important;
}
in the file /templates/rt_iridescent/css/rt_iridescent-custom.css but the class hikashop_inserted_product_1 is only for the first product (hence the 1 in the class name).
I would recommend to remove that CSS code if you don't want the blue buttons or change div.hikashop_inserted_product_1 a to .hikacart if you want the blue button for all the add to cart buttons.
2. That PayPal error is common. It means that there was already a previous payment with the same order ID placed with that PayPal account.
It can happen if you were doing test orders and then you deleted the orders and reset the order ID count to 0.
Or it can happen if you were previously using another ecommerce solution with that same PayPal account.
What you can do is change the order ID in HikaShop to start at 10000 for example instead of 0.
We actually have a documentation on that here:
www.hikashop.com/support/documentation/i...l-error.html#already
As you can see, both issues are not from HikaShop nor from the solution I gave you before but from other elements of your shop. You would have had the same issues with another ecommerce solution.