I've been using the green version of this chalk for years, have no reason to change, I've read quite a few reviews of people who have used the blue version and say it's different, the most common comment I've seen is that it feels creamier than the green and leaves marks on the cueball, TAOM says it's the same formula, my first thought was why would a reputable company like TAOM lie about it being the same formula if it wasn't? What would they have to gain by lying, didn't make any sense, my second thought was why would some guys on a pool forum lie about how it felt to them? That didn't make sense either, so I bought a round of the blue V10 and have been using it for the last 11 days for at least an hour a day, did it feel creamier? Yes, did it leave more marks on the cueball, Yes, but most of the marks would go away on their own, I can attribute some of that to the blue version being a darker blue and the green being a lighter green, so I've been pondering why did TAOM lie about not changing the formula, then it hit me, what if the formula of the dyes used to color the chalk was causing the change, it took me back to science class, oxygen is 2 atoms of oxygen or O2, ozone is 3 atoms of oxygen and if you breathe it will kill you, if one atom in a pure element can make that big of a difference what happens when you you mix a lot of different elements, logically it would have to cause more change, so what I've come to believe is both are true, TAOM didn't change the formula, but the dyes reacted differently with the untreated chalk, I can't prove it but it does make sense 
