Adds a legend to a static tetrahedral colourspace plot.
legendtetra(x = 0.8, y = 1.2, ...)
position of the legend relative to plot limits (usually a value between 0 and 1, but because of the perspective distortion, values greater than 1 are possible)
additional arguments passed to
legendtetra adds a legend to a static tetrahedral colourspace plot.
for additional information on which arguments are necessary and how they are used,