Color Change, it seemes like it could be a lot of funs especially on a tank. The only problem is consistancy....
Indeed. Color Change is overall a very gimicky and unreliable ability. First, you need to be able to come in on whatever attack you think your opponent is about to use, since Color Change doesn't apply until after you've been hit with an attack. If you end up mispredicting, you could wind up really hurt, and taking a lot of damage, or you could wind up being hit with a Ghost or Dragon attack and be hurting next turn. On top of that, there's also Normal, Fighting, and Rock attacks, which don't resist themselves, and thus it wouldn't exactly like mispredcting and coming in on something like Stratagem's Paleo Wave.
There's also the issue of a Color Change Pokemon, due to it's ability, not having any sort of reliable STAB moves. As a result, Color Change can be quite a hindrance to a defensive Pokemon, and there are numerous situations where it would have been better off without it, and have an ability that at least wouldn't have hindered it, such as Shield Dust.
Edti: Tennis, the problem with Static is that, yes, it is true that you can never know for sure what your opponent will do anyway, and how the RNG will roll, and so forth. However, with Static, even if you predict your opponent right and get them into a situation where Static activating is advantageous, there's still no guarantee of it activating. Static is the exact opposite of an ability such as Shield Dust. Whereas Shield Dust prevents some common forms of hax from affecting you, Static is hoping that you will get hax, and that the hax will be of a knd that works in your favor. Unlike an ability such as Levitate (which I know is not neglected; just using it as an example to make a point), which will always do it's job should you predict your opponent right, even if you do predict your opponent perfectly with Static, there's no guarantee that it will activate and be there to help you.
Another example: Sure, the guaranteed confusion on DynamicPunch is nice. But I'm pretty confident that you wouldn't use it on something other than Machamp, as that confusion is simply not worth the accuracy. Why then, would you want to have, or would want to rely on Static, which has a 20% chance less of doing its job than DynamicPunch? Would you not prefer even an ability like Shield Dust over it, which, even though you wouldn't know when it helped you, you would still at least know that it always would have been there when you got haxed, and didn't simply have a 30% chance of stopping the hax? I know I would; the chance of paralyzing my opponent might be nice, but I'd really rather just use a move like T-Wave than rely on Static, since at least with T-wave, I know that should I predict right, my opponent would become paralyzed, whereas with Static, I can't be sure, and I'd really rather avoid relying on luck if at all possible. I would also prefer Stun Spore, even without something like Compoundeyes, to Static; sure, it's not guaranteed, but it still has much more of a chance of doing the job than Static, and can also hit anything that's not immune to paralysis, unlike Static, which can only hurt things that don't have Limber OR that do wind up using a contact move against you.
Although, I suppose you do have a point with them being eligible for the poll regardless; I just feel that they aren't really the best of options, and am a bit concerned that we might get an ability such as Static just due to it looking like this Pokemon could quite likely be part electric, instead of it actually being in the Pokemon's best interest to have it. But again, I suppose that's just guesswork, and should have no effect on whether or not they're included on the poll.