GVIM : how to change the color of the text via ( /root/.vimrc ) file?

GVIM : how to change the color of the text via ( /root/.vimrc ) file?

Currently in
/root/.vimrc
i have
:colorscheme desert
set guifont=Monospace\ 11.5
in both cases i didn't know how to find these values, so others told me
about it.
in other words i do not know how to set the color of text to "#cccccc" for
example.