Rainbow
Red	Yellow	Blue	Purple
#FF0000	#FFFF00	#0000FF	#FF00FF
rgb(255,0,0)	rgb(255,255,0)	rgb(0,0,255)	rgb(255,0,255)
hsl(0%,100%,50%)	hsl(60%,100%,50%)	hsl(240%,100%,50%)	hsl(300%,100%,50%)