Why are villains often dark, but the good guys are light/white in movies, books etc?

curiousnorway
Often in books and movies the bad guys are portrayed as dark (Either hair/clothes/skin), but the good guy are portrayed light. Light clothes, hair (often blond) and white. I thinks it's quite weird they portrays them like that.

In Narnia for instance you knows the witch are the villain even though she's white and blonde. In the Golden compass you also gets the point very fast. It's easy to understand that the witches there are good even though some of them are dark. Same thing applies to the Disney movies Aladdin, Mulan and The princess and the frog. It's easy to know who's good and bad even for children without using the dark vs light stereotype. Therefor using the stereotypes where dark is bad and light is good doesn't make sense for me.
Why are villains often dark, but the good guys are light/white in movies, books etc?
In this movie they kind of follow this stereotype, but only when it comes to witches. If you're a human or a villager this doesn't seem to apply. You can just take a look at the witches and know who's good and bad. The villain and the second witch who turns into a villain is dark, but the good witch is light and blonde.
Why are villains often dark, but the good guys are light/white in movies, books etc?
In this movie it's easy to know who's the hero and the villain even though both of them are dark. So the stereotype aren't necessary to know who's good and bad.

PS! Please keep this discussion calm and peacefully when answering. You're allowed to be disagree.
Updates
+1 y
Do you think terms like black, white, red and yellow is stupid terms? Here we discuss our language:
www.girlsaskguys.com/.../q2332520-do-you-think-terms-like-black-white-red-yellow-is-stupid-terms
Updates
+1 y
Another related question. Do you think it's racist to portray the good guy light/white, but the bad guy dark?
Why are villains often dark, but the good guys are light/white in movies, books etc?
38 Opinion