The colours red and green, and yellow and blue cannot be viewed simultaneously. The human eye will swap back and forth to see each, but won’t actually be able to see them at the same time. This phenomenon is called visual opponency.
Some scientists have been working out a way to make people see these colours at the same. Something to do with following eye movements and stopping the eye from trying to cut away to the other colour. Sounds cruel, but I want to see what reen or blullow looks like.
