As casperBGD said, Leipzig missed many opportunities to secure the third place or even to annoy Dortmund in the second place. I am not saying they will lose for sure but I am not confortable with their performance to say they will win.
Koln will be the underdog team at home because they dont have enough motivation to improve their ranking in the table unless they are able to beat Leipzig with 4 goals without reply.
Although both teams will play offensively, but I think Leipzig will come out victorious in that match because the results will take them to 3rd place.