Change colours of mesh plot?

[Sebastian Schubert]

Hi,

is it possible to change the colours of a mesh plot?  I mainly want to
tune a grey-scale output for inclusion into a LaTeX document.  For
example, the peak in figure 15.5 in the pdf manuel (sombrero) is a bit
to light for my taste.

I use octave 3.0 and gnuplot 4.2.2 (although, if 4.2.3 is necessery,
this won't be a problem).

Cheers
Sebastian