i havent had any problems with discoloration but I have been experiencing some durability issues. For example, after one hole (no i didnt hit any trees or cart paths or things like that) the cover of the golf ball was peeling. I dont have very sharp grooves so i dont think that is the problem. I didnt have any problems like this with the previous pro v1x ,model so i would love to know why this happens to this particular generation of pro v1x. thanks and sorry i couldnt be much help, just wanted to share my experience.

I used the new Titleist Velocity   Performance is great   and a awesome putting ball   

Only problem  it shows wear real quickly   scuff marks just from irons   without hitting trees or gravel  the paint comes off small patches of yellow where the paint to gone. May not effect play  but  hard to look at    so I change balls     3 times in 1 round

Wish it just lost color   instead of  the paint chipping away  leaving bare spots.

No discolouration issues for me as well... just grass stains that can be wiped off. As for durability, the 2011 version gets scraped off easily, especially with well struck wedges. Which I didn't encounter as much with the 2010 version.

I know there were changes from the 2010 to the 2011 version... I am not sure with the 2011 to the 2012 version?

Noticed the durability issue too, obviously more so with the short irons. But if they aren't as durable, I guess we just keep buying more ProVs. Not good for us golfers who don't get them for free, good for Titleist. HMMMMMM, maybe we are on to something.

Bert ...you have nailed it except for the color ...I am amazed that millions of balls later TT would not have rectified this ...trying other brands since April ...will keep the world posted ...cheers