Hi @wordpresshelpnow,
There are multiple ways to remove the GiveWP Form Featured image:
1. Disable it at Donations > Settings > Display Options > Post Types.
2. On that same settings tab, disable the Single Form Sidebar
3. Add a featured image to the form (from the individual form’s edit screen) which will remove the placeholder and replace it with your image.
For your second question, try this CSS:
button.give-donation-level-btn {
color:blue;
background-color:white;
}
button.give-donation-level-btn:hover {
color:#0199d9;
background-color:aliceblue;
}
If you need assistance implementing custom CSS on your WordPress website, we have this guide for you:
https://givewp.com/documentation/resources/handling-custom-css-in-wordpress/
Thanks!