They also had a blue practice court last year and the year before too I think. They did this to test out the surface before making a decision whether to use it on match courts or not.
The title sponsor, the Spanish insurance company Mutua Madrileña wish to use it for better branding of the tournament because it's the color of their company logo. But some high-profile ATP players like Federer and Nadal have been against it IIRC.
Apparently they have not agreed to use it for matches yet. Maybe it never will, but I think it's just a question of time. For hard court they use several different colors for different tournaments anyway.
Last edited by stangtennis; Apr 30th, 2011 at 02:41 PM.