Same as color name "Tomato":

rgb(255, 99, 71)

#ff6347

hsl(9, 100%, 64%)

Same as colors name "Tomato", but 50% transparent:

rgba(255, 99, 71, 0.5)

hsla(9, 100%, 64%, 0.5)

In addition to tha predefined color name, colors can be specified using RGB, HEX, HSL, or even transparents colors using RGBA or HSLA color values.