Color – opaque

red=0deg, green=120deg, blue=240deg

Colors are used for text, backgrounds, borders, soon also for gradients and text decorations.

Keyword	Hex	RGB	HSL
aquamarine	#7FFFD4	rgb(127,255,212)	hsl(160,100%,75%)
-	#DC9074	rgb(220,144,116)	hsl(16,50%,66%)
coral	#FF7F50	rgb(255,127,80)	hsl(16,100%,66%)
-	#b73000	rgb(184,49,0)	hsl(16,100%,36%)
darkorchid	#9932CC	rgb(153,50,204)	hsl(280,61%,50%)
black	#000	rgb(0,0,0)	hsl(0,0,0)
gold	#FFD700	rgb(255,215,0)	hsl(51,100%,50%)

Color – transparent

rgba(R,G,B,alpha) and hsla(H,S,L,alpha)

hsla(20, 90%, 50%, 0.0)

hsla(20, 90%, 50%, 0.3)

hsla(20, 90%, 50%, 0.6)

hsla(20, 90%, 50%, 1.0)

Property 'opacity' makes the whole element semi-transparent