Train AD

I watched "Train AD" at YAMANOTE line,SHINBASHI station.
I was surprised by this brown train,because YAMANOTE line is
green train.
Key words "memorial of named as YAMANOTE 100 years ago"
were wriiten at the top of entrance,so I think YAMANOTE line
was brown train 100 years ago.And chocolate is also brown.
Normally "Train AD" wraps a part of train,but it covered
all of train.It was sponsored by Meiji confectionery.
http://www.sanspo.com/shakai/news/090907/sha0909070523001-n1.htm