Default colors 'list-colors-display'

[brian . auld]

I have gone cross-eyed the past day trying to find the answer to my question, 
but my efforts have not beared fruit. Hopefully someone can answer this for me.

I'm trying to add/change colors to my 'list-colors-display'. Ultimately, I want 
to get rid of the color 'cyan', and replace it with something else, as 'cyan' 
is next to impossible to read against a white background. 

Specifically it is for color coding 'C'. All other colors in my 
'list-colors-display' are used to highlight some part of the 'C' code, so if I 
simply change the face where cyan is used ('C' keywords) to another defined 
color, I will be duplicated its use with something else. 

I therefore want to add a color that will ultimately show up when I do a 
'list-colors-display'. It appears that when I go into a M-x customize ... I can 
only change colors to something that is defined under 'list-colors-display'.

Can someone point me to how I can add color definitions to my emacs.

Regards,

-- Brian

p.s. 

>From an emacs newbie trying to get on the emacs bandwagon