How to change the header background color in Next Experience UI(Polaris)SummaryHow to change the header background color in Next Experience UI(Polaris)ReleaseFrom Sandiego Instructions1-To override OOB CSS- create a new sys_ux_style and link to the Theme. Refer the below article for details steps Override Basic CSS Variables - Polaris Create a Next Experience style 2- In the newly created "sys_ux_style" - update the below property to the desired value. -now-unified-nav_header--background-color That should allow you to control the color of the navigation header