Hello,
Please add this code to the Theme Settings > Custom CSS > Global:
.wpcf7-form-control-wrap input[type='email'],
.wpcf7-form-control-wrap input[type='text'],
.wpcf7-form-control-wrap input[type='tel'],
.wpcf7-form-control-wrap textarea {
border: 2px solid red;
}
body input[type="submit"]{
font-size: 13px!important;
background-color: red!important;
color: white!important;
border-color: transparent!important;
border-radius: 20px!important;
}
Please replace the values and colors as per your needs.
Best Regards