@lidorsystems/integralui-web/quickstart/src/app/integralui/themes/dark/integralui.datepicker.dark.css

IntegralUI Web - Advanced UI Components for Angular

.iui-datepicker
{
    background-color: #363636;
    border-color: #121212;
    color: #c5c5c5;
}
.iui-datepicker-header-button-down span
{
	background-position: -192px -216px;
}