Please follow this article if you would like to customize the color of your Org Chart employee card
In the top (root) control, there is an in-line CSS editor. You can use it to apply your custom CSS to the control/page, but you will need to know how to identify the controls you want to change. Having an inline CSS editor makes it easier to include your changes in this page without having to reference any external files.Select the gear icon within the top (root) control of the web part
Open the styles editor to add your customized CSS for your web part
In my example below, I would like to change the Org Chart employee cards to blue.
I have added the below CSS to the styles editor to change the employee cards to blue. If you would like to change it to a different color change the text from blue to another color.