What causing the marbled and discoloured look of the greens at Pebble Beach during the US Open?

Brown is the new Green. Usga feels that watering less is beneficial to the ecosystems , and also thinks that green is only aestethically pleasing not required for good golf. So they scale back on the watering. There was a big article on this a few months back in Golf Digest. It will be a trend we see more and more of. As water supplies become more used and strained people will not like golf courses watering . So before this becomes a huge issue USGA is taking strides . More and more top level courses will allow more areas to go brown , which Ironically is going to help out the game.