Standards can have "bugs", and a standard that is not compatible with maybe 5% of the population is buggy.
Almost any standard that start "this is red and this is green" is flawed this way. This mean any future standard created as to look into this type of stuff (and i18n and localization and others) to not create flawed buggy standards. Old standards can be updated ... (maybe include lines of the same color but different contrast), but we all know how hard is to update standards. If I where one of these dudes, I would download/create a app for my iphone that recolorice video to change colours to others I could tell the difference. -- -- ℱin del ℳensaje.