Enable all the features of ShopCred Addons and head to the settings option.
When you open the settings, all the options will appear.
Choose the Direct Checkout feature and avail the options to design.
Simply, change the background color also the text and border colors to elevate the appearance of the Direct Checkout button.
Also, you can set the preferable colors while you hover the Direct Checkout button. Then click on save the settings.
Here, you can see the changes you made.