How do you change the screen colour depth from 16 bit to 24 bit

A.
Run gnome-display-properties and select the required depth from a drop-down box.

B.
Edit the relevant setting in the system section of the GConf database.

C.
Edit the Screen section in /etc/X11/xorg.conf and restart the X server.

D.
X.org offers only 8, 16 and 32 bit colour depths.