Color way off on my ST2010B monitor - help

I bought a ST2010B monitor yesterday to provide a second screen for my laptop (Dell Latitude D620 with NVIDIA desktop manager).  The monitor passes the diagnostic test (colors look great during that test).  However, the colors when showing my laptop are way off.  Reds look like dark black; green shows up as yellow; etc.  I've tinkered with all menus on the monitor.  Any advice?