what is colors

Answer 1

blue, green, black, white etc are colors,
you can use color codes too !
#000 = #000000

Answer 2

you can use words lik (black. green. red...) or hexadecimal contains six characters and numbers like #000000 for black and #ffffff for white. also you can use RGB (Red.Green.Bleu) like this RGB (258.168.100)

Answer 3

They can be used in words or each hexadecimal code prefixed with a # could be used