Other than the new yellow pearl (extreme flip), the rest are all highly polished solids with the same coverstock and the same shape core. The Yellow pearl's core has a slightly higher RG and slightly less differential. Any differences will be due to the colors. There are always some, usually relatively trivial, ball reaction differences between colors.

I hear this question a lot and it's a great question. What we've been told is that the Green/White will give a little more length and pop off the spot. The Blue/Orange is the earliest and even of the 3. The Yellow/Magenta one is in between these two. Note that these differences are minor, but these are the differences that the pros, reps, and headquarters have picked up on. From personal experience, I only owned the Blue/Orange and I can say it did pick up a little earlier than expected and actually made a pretty good medium oil ball for me since I'm a little heavy handed.

As charlest mentioned, the only small differences are due to colors alone since really bright colors appear to have more impact on ball reaction. Hope this helps!

ON EDIT: The Yellow does have the pearl cover whereas the others do not. I do own the Yellow Misfit Pearl and it really scoots downlane. It's saved my butt more than enough on the drier/burnt up conditions. All cores are the same in all 4 balls.

I thought the yellow misfit core has a lower differential...

Thanks for the info. Which one hooks more, the pearl or solid?

If its dry, the Yellow will definitely hook more because it is a backend fiend, but it won't do much in oil. 
Something interesting I heard from Team Canada coach Ty Rose (who also writes for BTM), "If all things are to be equal, pearls should OUTHOOK solids due to how strong they can be on the backend."