Simple DesignationFitzpatrick Scale (Skin Type Association)Modified Martin-Schultz Scale (1–16)Classic Martin-Schultz Scale (A–D)1998 Eye Chart (A/D/T Codes)Heterochromia Classification (Measurement Method)BlueType I–II (very fair skin)1–2: Blue irisA10–A19 — Blue shadesA10, A17, A40, A50, A60Partial: 70% Blue (A17) + 30% Hazel (C25)
Full: LE: A17 (Blue), RE: C25 (Hazel)Blue-grayType I–II3: Blue-gray irisA20–A25 — Blue-grayA20Partial: 60% Blue-gray (A20) + 40% Green (B15)
Central: Inner A20, Outer B15GrayType I–II4: Gray irisA25–A29 — Light grayD10, D20Full: LE: A25 (Gray), RE: C20 (Hazel)GreenType II–III7: Green irisB10–B19 — Light greenD30, D34, D37, D40Full: LE: B15 (Green), RE: T15 (Brown)HazelType III–IV9–11: Light brown and hazel irisC10–C19 — Light brown (amber)D50, D60Partial: 60% Hazel (C15) + 40% Green (B15)Light BrownType III–IV9–11: HazelC10–C19 — AmberT07, T10, T15, T17Full: LE: C10 (Light Brown), RE: D10 (Dark Brown)Medium BrownType IV–V12–13: Medium brown irisC20–C29 — Medium brownT20, T30Partial: 70% Medium Brown (C25) + 30% Green (B10)Dark BrownType V–VI14–16: Dark brown/black irisC30–C39, D10–D19 — Almost blackT40, T50Central: Inner D15 (Dark Brown), Outer T40 (Chestnut)BlackType VI16: Nearly black irisD15–D19 — Almost blackT50Full: LE: D19 (Black), RE: C30 (Dark Brown)