Thanks for letting us know about the situation. We'd love to help you with this.
We have options to change the Background color, Border settings, and Padding of the Slider.
To change the background color of the slider in Mobile view follow these steps:
Mobile view-> Menu tab-> Menu button properties-> Slide Panel-> Background
We've attached a screenshot below for your reference.
We hope this is helpful. Let us know if you have any more questions, comments, or concerns.