Selected/Active style for value display.

Hi,
I was using a button in a mashup and then displaying it in a collection widget in another mashup such that each cell has a button. When I click one button in my collections I want a style or color change so that the user understands that it is selected, but the ptc button's selected style doesn't seem to work and so I thought I will use a value display widget but I am not sure of how I will set a selected or active style for the same. In fact I don't see any change in my value display widget although I set a border color for it.I also tried adding some css but couldn't see any change.

So any idea how I could achieve this using a value display widget if not is there any other widget I could use to get the required result?
The version I am using is ThingWorx 8.5.6.