The ncurses function extended_color_content was introduced in 2017

(https://invisible-island.net/ncurses/NEWS.html#index-t20170401).  The

ncurses-devel package in CentOS 7 had a older version ncurses resulted in
compilation error.  For compiling ncurses with extended color support, we
verify the version of the ncurses library >= 20170401.