Before you hit save there is an important setting we have to adjust. This part took me quite a while to figure out until it worked correctly. If you exported the the project with its current gamma settings and uploaded your animation on your Instagram account you would encounter a nasty surprise: The video gets way too bright! In order to solve this we can set up the right Timeline Color Space.
Please note: The setting I will present below will slightly brighten up your animation. I am still looking for a solution for this. If you happen to know anything about it please contact me. So far I only found a clunky workaround with QuickTimePlayer on Mac. Please contact me if you are interested.