Yorkiesmiles - did you also start the Missing Link along w/ the Wellness, at the same time? If so, I'd try eliminating the ML for awhile. Remember that ML is mostly fiber - so this may be causing the different poos.
Dark poos are not necessarily a bad thing. If they are tarry, that's bad. But just being dark doesn't necessarily mean anything bad.
If the paw licking has decreased, then it may indicate that they are allergic to some previous protein. If you do want to stick with this kibble for awhile, you might try eliminating the ML and/or adding a simple canned fish-formula and see if added moisture helps a bit. Glad to hear about less licking!!!
