Change overlay colour and transparency, remove shadow?

Hi,

first steps with your plugin, looks promising that it is what I was looking for.
Two questions though regarding the appearance:

1) I’d want to change the colour and opacity of the overlay colour. What would be the correct selector?

2) I’d prefer to remove the popup’s shadow effect. I assume that’s also manageable via css? Could you give me the correct selector?

Thanks in advance.