Checking monitor error when installing Oracle 10/11g on Linux

Error mesage like:

Checking monitor: must be configured to display at least 256 colors    Failed <<<<
>>> Could not execute auto check for display colors using command /usr/X11R6/bin/xdpyinfo.
Check if the DISPLAY variable is set.
Some optional pre-requisite checks have failed (see above). Continue? (y/n) [n]
Resolution:
Install the following rpm packages:
XFree86 xf86tools cabextract libpng libjpeg XFree86-Mesa