How many colours are there?
There is no number to be given, as colors are endless! Yes, the main one are seven: red, orange, yellow, green, blue and dark blue, purple. They all together make white color. However, scientists have carried out a research. It shows that most folks can distinguish up to 100 shades or red and green, and, what is best over 1000 shades of light-dark. A PC uses over 16 million colors to create a picture you see on the screen. The color you see mainly depends on the light. There are millions lighting types, so if you multiply it by 16 million colors you get a very large number. So, infinity is the best answer to give.