.enabled.dx-radiobutton-checked .dx-radiobutton-icon .dx-radiobutton-icon-dot {
    background: red;
}

.disabled.dx-radiobutton-checked .dx-radiobutton-icon .dx-radiobutton-icon-dot {
    background: gray;
}

.unspecified.dx-radiobutton-checked .dx-radiobutton-icon .dx-radiobutton-icon-dot {
    background: green;
}