Problem to change colors

["Ezequiel" <hreyes seg inf cu>]

I am new to Gnome, I have RedHat 6.0 with the Gnome version that comes with
it and I am trying to change the colors of the windows (not the panels, but
the rest of the windows), the only program that seems to do with that is
Color Browser, but it only let me see the colors, not to apply  them. Am I
missing any application like "color selector" or something ? I even tried
changing parameters on the gtkrc files located in the /usr/share/ ..
themes/,  using float format to change what seems to be RGB patterns but I
think, there must be a more visual way to do it.
One more question, I know this doesn't have to do directly with Gnome but
perhaps someone can give me a hint:
When I installed Linux, I was asked to chose from a List of available
resolutions/color depths after testing my video card. What I don't
understand is, I only have 1 MB video RAM but the there was a higher
resolution in the list than 1024x768 / 8bits colors. I tried that one just
for a test, and the image on the screen turned so distorted I could hardly
see anything.
The question is: Was the resolution above 1024x768 a mistake of the
Xconfigurator or it is just a problem of refresh rate ?