Do you have old hanging metal fluorescent lights in your office that you can't turn off or are shared with another mate?  Then these are for you.  Set them to the height you want and print the covers.  Want to block light? Black.  Mood colors?  Warning colors?  Want a rainbow?  All is possible.  I know there are other options but these snap on the existing parts so that nothing gets lost.  Printed in PLA and has been holding up for months so far.