Enums with string values return the enum key instead

[justinrusso]

Given this enum:

public enum Stage {
  Colorless = "colorless",

  Red = "red",
  Green = "green",
  Lime = "lime",
  Blue = "blue",
  LightBlue = "light_blue",
  Gray = "gray",
  LightGray = "light_gray",
  Yellow = "yellow",
  Purple = "purple",
  Magenta = "magenta",
  Pink = "pink",
  White = "white",
  Black = "black",
  Brown = "brown",
  Cyan = "cyan",
  Orange = "orange";
}

Attempting to use Stage.LightBlue results in a value of lightblue.