painting the screen is easy
key the back with 240 grit wet and dry
wash with soapy water (do not use thinners)
then spary with halfords car body paint
then spary over the colour with matt black if needs be
remember the colour will get darker if backed with matt black
always test a small area first
just in case the paint reacts with the screen

the same method is used on rc car bodies
they are painted on the inside of the body
and will take a good bashing before the paint flakes off

cut an old plastic pop bottle up and use that to have a practice