.webform-submission-form .form-item select {
    background-image: linear-gradient(45deg, transparent 50%, #d00a2c 50%), linear-gradient(135deg, #d00a2c 50%, transparent 50%), linear-gradient(to right, #ccc, #ccc);
}
.webform-submission-form .form-item select:focus { 
     background-image: linear-gradient(45deg, #d00a2c 50%, transparent 50%), linear-gradient(135deg, transparent 50%, #d00a2c 50%), linear-gradient(to right, #ccc, #ccc);
     background-position: calc(100% - 15px) 1em, calc(100% - 20px) 1em, calc(100% - 2.5em) 0.5em;
}