Please be so kind as to read my full post before responding.Thank you for your consideration.
Originally the Date Picker control only allow changing the sizes and colors of the "Text Part" of the control.Since November, there is now also the option to change the colors of the Calendar icon.
https://powerusers.microsoft.com/t5/PowerApps-Ideas/Changing-the-coulour-of-the-date-picker-in-the-E...However, the colors, size, and font size of the Calendar popup that appears after clicking the icon seem to unmodifiable.
Thank you, Sa
Please fix this as it ruins the colour palette of the application when the date picker is blue and uneditable.