http://www.google.pl/logos/white_logo-276x110.gif

This doesn't trigger any link, i.e. it's a memorial doodle for victims.

Yes, see
http://www.metronews.ca/toronto/world/article/500765--thousands-pays-their-respects-as-president-lech-kaczynski-and-his-wife-lie-in-state

Most websites turned B&W. Despite its black ribbon, Google contrasted too much with the local intertubes (see http://globalvoicesonline.org/2010/04/11/poland-online-grief-after-10-04-2010/).