Gray out clicked buttons?

I thought this feature was added, but I must not be using it properly?

I have two buttons on a page: Pie Chart and Bar Chart

When I click "Pie Chart" I want the button to be grayed out or darker background (something to indicate it was clicked).  
Then when I click "Bar Chart" I want to return "Pie Chart" button to normal and gray out or fill/darken the "Bar Chart" button.

I cannot find a way to make these changes.

I can adjust the FILL to use "On Press" but that only changes while the mouse is clicked.

How can I create button effects so that the most recently clicked button looks different than the other buttons on the page?


There is not a "Selected" state.

Should I be using conditional formatting to achieve this somehow?