Is God white?

'Mum, God is white,' exclaimed my son as we sat watching TV. Taken aback, I explained to him that God wasn't white, Chinese, Indian nor black, God is a spirit! I could not blame him and many other black children(or other non-white children) for thinking this way because all their children bibles are filled with God( usually depicted as a white grandpa sitting in the clouds) and all other biblical characters as white, with the image of Jesus as Blond with blue eyes.

Since that incident, my children's bible are illustrated with Afro Caribbean people. Yes, even Jesus is illustrated as black. Why is one person 's (a group, in this case) illustration of Christ/ God more important or accurate than my own especially when it's about the message, not ethnicity?