Hi Luigi,

The example works if one copies colo-rgb.mkii as colo-rgb.tex in the same
folder of the example ...

It is OK by changing

line 46 in m-pstricks.mkii:
  \loadpstrickscolors{colo-rgb}}
to
  \loadpstrickscolors{colo-rgb.mkii}}

as Herbert said.

In the recent beta's, the change was already done.