phpengine/ui/custom.css

body {
    background-color: #1c1c1c !important;
    color: #c5ac0f;
}

input[type="text"], input[type="password"] {
    background-color: #484848 !important;
    border-color: #C5AC0F
}

input[type="text"]:focus, input[type="password"]:focus {
    border-color: #C5AC0F;
    color: orange;
}
.form-control {
    color: orange;
}

.form-control:focus {
    border-color: #c5ac0f;
    box-shadow: 0 0 0 0.2rem rgba(197, 172, 15, 0.25);
}

.debugborder {
    border: 1px solid red;
}