Can I define Color for my different Business source?

Yes, we can define different for different business sources.

 We can achieve such set up by changing the color, please refer to the below steps.

By Business source:

Path: Absolute Configuration--> Masters Tab--> Marketing--> Business Source--> edit

• Edit the Business Source--> Internet Booking Engine--> Change the color to "BLUE" 

The same way you can define your color for different Business sources.