[UI Bug]: DatePicker and DateRangePicker have transparent background (should be white)

[christoph2806]

Short Summary

The DatePicker and DateRangePicker components have a transparent background, which should be white.

Steps to Reproduce

1. Create DatePicker or DateRangePickerComponent and open it.
2. The background is transparent

Expected Behavior

Background is white

Actual Behavior

Background is transparent

Browser & Device

No response

Screenshots

No response

Additional Notes

No response