how to change mouse pointer color

[George Nurser]

I am using  v22.0.90.2 of emacs on a linux host, viewed on a Mac
through X11. It is giving me a yellow mouse pointer
[hand/arrow/ibeam]. As I use a white background this is not working
well.

I tried adding
(set-mouse-color "black")
to my .emacs, both at the end and beginning but it seems to have no effect.

How do I change its color?

George Nurser.