[Theme Horse Support Team]

Hello there,

To change the background color of sidebar just use the below custom CSS code:

#page:before {
	background-color: #ffffff;
}
@media only screen and (max-width: 767px) {
	.main-navigation li,
	.main-navigation ul li ul li {
		border-color: rgba(0, 0, 0, 0.2);
	}
}
@media only screen and (max-width: 767px) {
	.site-header {
		background-color: #ffffff;
	}
}

Note: Change above HEX color code #ffffff to your own HEX color code to change the background color.

Thank you!