runinstaller Could not execute auto check for display colors using command /usr/bin/xdpyinfo

 Hi all,

On Linux 8.7, Looks like some x components are missing. Please advise how to check which component?

$ ./runInstaller

Starting Oracle Universal Installer...

Checking Temp space: must be greater than 120 MB.  Actual 38653 MB  Passed

Checking swap space: must be greater than 150 MB.  Actual 5119 MB  Passed

Checking monitor: must be configured to display at least 256 colors

  >>> Could not execute auto check for display colors using command /usr/bin/xdpyinfo. Check if the DISPLAY variable is set.  Failed <<<<

Thanks

a friend