Screen appearance - Colour

[Dave Delaney]

Hi folks

I hope I am mailing this to the correct list, apologies if I have not.

My new job involves me using Linux. I am visually impaired and would like to
set up the screen
to be a black background with white text. I can do this for the terminal but
can't find how to change the Gnome colour to a global setting. In Windows
2000 this can be done in the Control panel, Display, appearance, here you
can select high contrast.

I would appreciate any pointers.

Thanks
Dave