Darker theme for dangrossman's bootstrap-daterangepicker. (github.com/dangrossman/bootstrap-daterangepicker)

style.css

/* Darker Daterange Picker */

.daterangepicker td.off, .daterangepicker td.off.in-range, .daterangepicker td.off.start-date, .daterangepicker td.off.end-date {
  background-color: transparent;
  color: rgba(200,200,200,0.5);
}
.daterangepicker {
  background-color: inherit;
  color: #ebf4f0;
}

.daterangepicker .calendar-table {
  background-color: transparent;
}

.datepicker.dropdown-menu table  {
  background-color: transparent;
}
.daterangepicker td.active, .daterangepicker td.active:hover {
  background-color: transparent;
  color: #ebf4f8;
}
.daterangepicker td.in-range {
  background-color: rgba(37,47,57,0.9);
  color: #ebf4f8;
}
.btn-success {
  color: #fff;
  background-color: inherit;
  border-color: rgba(5,150,1,0.8);
}
.btn-success.disabled, .btn-success[disabled], fieldset[disabled] .btn-success, .btn-success.disabled:hover, .btn-success[disabled]:hover, fieldset[disabled] .btn-success:hover, .btn-success.disabled:focus, .btn-success[disabled]:focus, fieldset[disabled] .btn-success:focus, .btn-success.disabled.focus, .btn-success[disabled].focus, fieldset[disabled] .btn-success.focus, .btn-success.disabled:active, .btn-success[disabled]:active, fieldset[disabled] .btn-success:active, .btn-success.disabled.active, .btn-success[disabled].active, fieldset[disabled] .btn-success.active {
  color: #fff;
  background-color: inherit;
  border-color: rgba(5,150,1,0.1);
}
.btn-default {
  color: #fff;
  background-color: inherit;
  border-color: rgba(255,255,255,0.6);
}
.daterangepicker select.monthselect {
  color: rgba(37,47,57,0.9);
}
.daterangepicker select.yearselect {
  color: rgba(37,47,57,0.9);
}
.daterangepicker .input-mini {
  color: #ebf4f8;
}