Because art is a symbol or status of living. rural cultures out in the middle of nowhere fighting to survive don't have time or resource to create something. but rich countries or cultures with money to blow have no problem spending on something cool they can create. plus it shows the world a bit of that countries style and flavor
red, yellow, and blue are considered primary colors because every color in the visible spectrum of light is a combination of those colors
Sometimes its due to age of the hieroglyphics your looking at
