 
 			if model == "rgba" || model == "rgb"
 
+				# rgb model
 				result = new Color
 					r: Utils.modulate(fraction, [0, 1], [colorA._r, colorB._r], limit)
 					g: Utils.modulate(fraction, [0, 1], [colorA._g, colorB._g], limit)

			else if color.hasOwnProperty("h") or color.hasOwnProperty("s")

				h = if isNumeric(color.h) then color.h else 0
				s = if isNumeric(color.s) then convertToPercentage(color.s) else 1
				if _.isString(color.s) then s = numberFromString(color.s)



			else

				# hsl model
				hslA = colorA.toHsl()
				hslB = colorB.toHsl()

