let RGB = { r : Natural, g : Natural, b : Natural }

let RGB/create =
	  λ(r : Natural) → λ(g : Natural) → λ(b : Natural) → { r = r, g = g, b = b }

let RGB/show =
		λ(r : RGB)
	  → "rgb(${Natural/show r.r}, ${Natural/show r.g}, ${Natural/show r.b})"

in  { white = RGB/create 255 255 255, black = RGB/create 0 0 0 }