Well, you might think of white fluffy clouds and think white is the perfect sleeping colour and then because it is dark when you sleep, maybe black is the correct colour. However, pink is the perfect colour and not because of the actual colour, but because of the even distribution of noise that it distributes!
Pink noise is a steady drone of sounds that help to slow and regulate brain waves for a deeper and more restful sleep.
Pink noises can come from even sounds like fans, but you can also download the sounds on your phone.
While sleeping in the correct colour is important, make sure your going to bed routine also entails you slowing down at least half an hour before sleep, having zero caffeine in the evening and an enticing, comfortable sleeping space.