A couple of answers:
The name change came with an ownership change. Doug Manchester, the man who owns the Grand Hyatt downtown (and a lot of other things), bought the course and renamed it. Mr. Manchester is building a large resort at the golf course called The Grand Del Mar. Basically, they named the golf course after the soon-to-be resort. They tried Del Mar National for a little while but that didn't stick.
The fairways definitely have a brownish tint, at least, in the winter. The nights get cold enough for the fairways to go a little bit dormant. In fact, there are occasionally frost delays in the winter, especially because several holes are routed through narrow coastal canyons that get very cold and then don't get much sunlight in the mornings.
There has been talk about overseeding the fairways in the winter because a lot of people ask them, "Why aren't the fairways green?" The grass in these pictures is a bit greener than it is in the middle of winter. So for they have avoided overseeding because it obviously brings up a lot of problems. The playing surface in the winter is very tight. (If I remember right maybe just the tees are overseeded?)
While I'm at it, a few more facts about the course. They're recently made changes to three holes:
#5 went from a very narrow 310 yard par-4 to one of the narrowest 385 yard par-4's you can find.
#6 was extended from 125 yards to 175 yards. In both cases the course was finally allowed to build tees in a particular part of a canyon they were not allowed to use when the course was built.
The flow of the course used to be really broken up by holes 5-7, which interruped a difficult front nine with mismatched holes of 310, 125, and 525 (from the tips). Now the course flows much better.
Also, #16 and #17 were supposed to be about 510 and 180. Instead, they were told that the canyon on #16 was too narrow for a par 5, so it was shortened to a 410 par-4. The green on 17 was already built, but the old tee angle across the water was changed which is why #17 feels like you're coming into the green from the side. Now #16 is becoming a par-5, as originally intended.
Interestingly, 9 holes on the course had to be substantially changed from the initial routing due to environmental or land planning concerns unrelated to housing. Mr. Moore did a great job explaining to me that people have no idea of the compromises Fazio had to make with the course - and, of course, that they'd only judge the course based on the final result, regardless of whatever challenges were faced along the way.