The green on the hill is called Hydroseed. The green color covers the seeds and provides nutrients until it gets established. They use this to help keep the hillside from sliding.
Fun Fact: As I heard from the Cast Member, when I went there on March 17th, the cast member says every week they add a new Glamour Tram when I went there on the 18th there were 2 now I think there are 5 and the Studio Tour will only have 8 Glamour Trams so by the summer it will be kinda rare to catch one of those 8 Glamour trams especially during packed season at Universal Hollywood.
