It is an another interesting feature in Dynamics 365 V9.X.
Below example is to change the Contact’s Subgrid Panel Header Color in Account Form.
1. Open Account Form and double click on Contacts Subgrid.
2. Now, we have an option to see the Panel header color to provide.
By default it is #F3F3F3 Hexa decimal color code.
3. Click here and get the required Hexa decimal color code and provide the same in Panel header color in Subgrid Properties and click OK.
4. Save and Publish the Account Form.
5. Open any Account Record to see the Colorful Header.
Hope you liked this new feature in Dynamics 365 V9.X.