Over the years i have noticed that a Titleist Pro V1 and the V1x seem to not stay as “pure white” as some other balls with respect to their original brightness. To me it is a subtle occurrence that should not affect play.

I play the ProV1 but have not seen any discolor and our course has been rather wet and muddy. I’m like you were always keeping ball clean.

I haven't noticed any more discoloration after play than with every other white ball I've used. Heck - I didn't even know they weren't supposed to get dirty after play.

Guess it depends on how many times you hit the ball. Grooves can take some of the luster off any golf ball.

As you look at this picture, you can definitely see the difference between the new balls and the balls that each have been played for 1 round. The balls that have been played looked like they have been used for years of play.
I thought that something in the outer compound may have changed with the 2025 version of the x that has caused this breakdown in color.

Could be. Every release they try to improve the performance of the ball. I would think that if it comes down to a choice between a little discoloration vs better performance, they're going to go with the performance.
It really doesn't affect my game. My concern leans more towards being able to finish a round with the same ball I start with.

Nope, but contributing factors can be golf course fertilizer, abrasive cleaning with brush-lined ball cleaners, or some strong soaps that might be used in cleaning buckets. I find that it takes 3 or 4 rounds for the sheen to wear off on my ProV1x’s.

Interesting observations, Dale!! I am not sure what is causing this because I clean the balls with a towel, no groves or brushes, with clean water, no detergents. I’m sure the courses here in the Naples, Florida area do use plenty of fertilizer.
I started noticing the difference with the 2025 version. I play an average of 170 rounds per year. That adds up to a lot of golf balls being purchased if they only stay white for 1 round. I do not see the discoloration with the yellow balls though.

I would be interested to hear what the Titleist scientists think as well!

It does seem that there appears to be some discoloration involved over time. I was thinking too that the discoloration tendency and/or discoloration rate may not be the same from one type of Titleist to another (i.e., ProV/V1 vs AVX vs TourSoft vs TruFeel --- but I could be wrong. I suppose soil type and characteristics could also play a role - but to what level, I am uncertain. What say you?