I dont think it matters if they're the same colour, all my skins use the same face for all ages, although i've only ever made 1 skintone
i just pasted the face over each age, i hadn't seen this tut until just now.
BTW, does this mean the same as basically removing saturation marks???
To get a nice colour i use alot of saturation, which looks good on paper but in Body Shop it just shows pixelated patches in places which looks rather unnatrual.