changing colour,contrast and other display features

[anupash.cool]

I have recently installed fedora core 6 ....since the resolution was less than the normal resolution supported by my graphics card ...i had installed 915resolution package .....
but now my display is dull ...i do not get a good output on my screen....can neone tell me how to change the color and contrast settings

[s-strong]

If in KDE You can change colors in the Control Center.

[anupash.cool]

i usually use gnome ....