With all the players at the Madrid Open having now taken to the new blue claycourts in the Spanish capital, we take a look at what some of the leading figures have had to say about it.
Novak Djokovic, world number one
"Not a single player - not woman, not man - I didn't hear anyone say 'I like blue clay'.
"It's impossible to move. I hit maybe five balls, the rest went just trying to put the ball into the court. I was relying on serve and getting free points from his (my opponent's) unforced errors.
"That was not tennis. Either I come out with football shoes or I invite Chuck Norris to advise me how to play on this court. I cannot find the words to describe this court. It's really tough to play like this on a centre court.
"We cannot change anything this year, but my first impressions are not good. I don't want to be the one complaining, but I say honestly what I feel.
"We need serious discussion about the future of this blue clay."
Rafael Nadal, French Open champion
Before the tournament: "My criticism is not directed at the tournament but at the ATP, which should never have allowed such a change at a tournament of this scale."
After his first match: "I think it's a bit far from being a clay court.
"The court is not one that makes you feel comfortable.
"It is a difficult court, it's very slippery and it makes supporting movements and getting back to defend very tough.
"But the only thing we can do now is turn the page and we are not going to get the red courts back tomorrow so we have to adapt to the blue courts and the conditions as well as possible and hope for a change next year."
Roger Federer, 16-time Grand Slam winner
"These are some of the fastest courts on tour."
Nicolas Almagro, world number 13
"Being so close to Roland Garros, we would prefer to play on red clay. This surface isn't in the best of conditions.
"It is very slippery and I hope there aren't any injuries."
Maria Sharapova, world number two
"It's not so much about the colour. It does look good on television. But it plays a bit different.
"It's about the amount of clay on the court and the way it bounces. You have to get used to it but I came here after winning Stuttgart and got in four or five days on it.
"I got settled in so it's just a matter of adjusting. It's also the same for everyone."
Caroline Wozniacki, former world number one
"It's definitely more slippery, but then I also completely stopped at one point. You could say it wouldn't happen on red clay, but then you never really know, it could be the same.
"It's definitely different, but blue is one of my favourite colours, so I do like the look."
Victoria Azarenka, world number one
"The bounce is different, the movement is different...it's just 100 per cent different."
Petra Kvitova, Wimbledon champion
"It's different playing on blue clay, but not that different really - it's still clay, and Madrid and Rome are going to be very good preparation for Roland Garros coming up."
Serena Williams, 13-time Grand Slam winner
"I haven't noticed a difference between the blue and the red clay. I think it's the same, it's just you don't get as dirty."
Spokesperson, ATP World Tour
"The ATP granted this permission for one year with the understanding that it will be reviewed following the event, of course taking into account feedback from players.
"We believe it is a good thing that our tournaments are trying to be innovative."
Ion Tiriac, tournament consultant behind the blue idea
"It looks like the court is too slippery and we have to fix that.
"But today, five days into the tournament, I am more convinced than ever that blue clay is a great step forward.''
You can also let us know your views on the blue clay by emailing us at firstname.lastname@example.org.