Main Menu Transparency

My site is test4.franciscanfriars.org I am not sure what I did, but the main menu (at very top) used to be semi-transparent (you could see header image behind it)... That seems to have gone away now... I would like to regain that feature... I was in Customize==>Color Options==>Primary Menu Color options.. and I changed everything, but have returned Menu Background Color and Menu Color to their default positions... but the menu no longer seems semi-transparent.. Also if I every do get it back to semi-transparent, can I adjust it's transparency? Thanks.