In the following code:

type color = [`Red | `Blue | `Green | `Black | `White]

let color_index c = match c with
  | `Red -> 1
  | `Blue -> 2
  | `Green -> 3
  | `Black -> 4
  | `White -> 5

type value = [`Red | `Blue | `Green | `Missing]

type state = Color of int | Missing

let state_of_value v = match v with
  | `Red -> Color (color_index `Red)
  | `Blue -> Color (color_index `Blue)
  | `Green -> Color (color_index `Green)
  | `Missing -> Missing

is there any way to write the last function as

let state_of_value v = match v with
  | `Red  | `Blue  | `Green -> ?????
  | `Missing -> Missing

martin