I would definitely use Mercedes Benz original anti-freeze only!
It is a light yellow color, and is unique in that it has a neutral Ph. If you put some in your fingers and rub them together, you can also tell that it has a very lubricitous quality to it. It almost feels like motor oil in this regard. I'm told Mercedes makes it this way to keep the water pump and hoses in good shape.
As an anecdotal aside, I used regular green anti-freeze in my car once, and within a several month period, my water pump failed, and three different radiator hoses / heater hoses sprung leaks.
I learned my lesson.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".