From: http://www.bbc.co.uk/worldservice/learningenglish/language/2013/11/131112_todays_phrase_black_and_white.shtml

Black and white

Woman surrounded by pandas
A woman sits among panda bear sculptures at a World Wildlife Fund event in Germany. Photo: Thomas Peter/Reuters

Today's Phrase

If a situation is black and white, it means you have a clear opinion about it. You can easily see what you think is right and wrong.
Examples:
I'm really sure about some things. I think free education for all is a black and white issue.

The question of nuclear power isn't black and white. Many people believe it is the only way to produce a large amount of clean energy – but many others think it has considerable dangers.

Similar phrase

If something is in black and white, it means it is written down.
Example:
I couldn't believe I had won the lottery, but when I checked my bank statement there it was in black and white: one million dollars!

Interesting fact

Giant pandas are famous for their love of bamboo, and it forms over 90% of the animal's diet. Unfortunately, bamboo has very poor nutritional value, meaning pandas have to consume up to 20kg each day to survive.