I have the same problem with my Marx Bothers and Charlie Chaplin D.V.D's.
It could be if the T.V. set is old and getting on a bit, that it is getting confused and thinks you only have a B&W licence.
Maybe your toner catridge in the TV is getting low, so only outputting in B&W, pop down to Curry's and ask if they have a colour refill for your TV, don't get the cheap ones off Ebay the clog up easy.
Play the D.V.D's on your PC is an option, but that may impact on your forum use

Last option pop into your neighbours house and use thier DVD player, I am sure they will be glad of your company and quick wit.
David