Creates (and optionally draws) a grid frame grob representing a color
  key that can be placed in other grid-based plots. Primarily used by
  levelplot when a color key is requested.
draw.colorkey(key, draw = FALSE, vp = NULL)A grid frame object (that inherits from "grob")
A list determining the key. See documentation for levelplot,
    in particular the section describing the colorkey argument,
    for details.
A scalar logical, indicating whether the grob is to be drawn.
The viewport in which to draw the grob, if applicable.
Deepayan Sarkar Deepayan.Sarkar@R-project.org
xyplot, levelplot