Ha ha yeah humans sure are great at not being convinced by the opinions of other people, that’s why religion and politics are so simple and society is so sane and reasonable.
Helen Keller would belive you it’s purple.
If humans didn’t have eyes they wouldn’t know the colour of the sky, if you give an ai a colour video feed of outside then it’ll be able to tell you exactly what colour the sky is using a whole range of very accurate metrics.