This PStricks package covers all the colour gradient
functionality of pst-grad (part of the base pstricks
distribution), and provides the following facilities: it
permits the user to specify an arbitrary number of colours,
along with the points at which they are to be reached; it
converts between RGB and HSV behind the scenes; it provides
concentric and radial gradients; it provides a command \psBall
that generates bullets with a three-dimensional appearance; and
uses the xkeyval package for the extended key handling.