[xmonad] Help: How to disable font smoothing?

Hello everybody! I just moved from gnome to xmonad and think it's good. I prefer fonts not to be smoothed, so in gnome I use gnome-appearance-settings and set the smoothing option to 'none' (other options are 'gray scale' and 'subpixel'). How to configure those in xmonad? (By default, the fonts in firefox in xmonad are smoothed.), and how to set the background and text colors of applications in general? -- Sincerely, Yuliang Wang