If you visit the Google home page globally, you will see a little white ribbon on under the search box.
If you hover your mouse over the ribbon, the tool tip will read:
International Day for the Elimination of Violence Against Women
If you click on it, it will try to take you to unwomen.org.
But because of the power of the Google home page, unwomen.org is not able to currently handle all that traffic.
If you want to see it, you can go to the text cached version on Google's servers or keep trying later.
Google UK said on Google+:
Today on google.co.uk there is a white ribbon to represent the +United Nations International Day for the Elimination of Violence against Women.
This evening +UN Women will host a live Google+ Hangout On Air to discuss their 16 days of action - join the event and watch live from 6pm GMT here: http://goo.gl/BSOmQj
You can read more on the +UN Women Google+ page or on their official website: http://goo.gl/N7AOId
Forum discussion at Google+.