dovc: Associate a color vector to a data vector
In MenuCollection: Collection of Configurable GTK+ Menus

Color vector definition for multiple plots

dovc(d)

`d`	data vector (numeric or character) of arbitrary length

Define a color for each data following these criteria:

if d is a character vector with length <20 : output a fixed list of different colors
if d is a character vector with length >20 : output a list of colors from the rainbow set
if d is a numeric vector: output a list of colors in the blue-red scale

Color vector of the same length of the input data vector

Gianmarco Polotti