Hello,
I saw the screenshots you attached.
1 &3 ) To add a background color and change the text color try adding the following Custom CSS in the Global Custom CSS area under Theme Settings >> Custom CSS.
.wd-search-form .searchform input[type="text"] {
color: black;
background-color: white;
}
2) Please try adding the following Custom CSS in the Global Custom CSS area under Theme Settings >> Custom CSS.
button.searchsubmit:hover {
background: #fd4680;
}
Regards.
Xtemos Studios