Cool idea, neat presentation. Music and graphics are great. So are the little machines, and the fact that you have to walk back up in case you forget the order.
As others have noted, the ink mechanic is not so fun. I did not get the game at first, because I thought there must have been more to it. But it was that simple. Of the top of my head I would propose any of the following:
If you had to put on specific bags/bottles for each color, and then you can only pick up that color, while the other colors spawn much more often, it would at least require some thinking.
Or if you still have the entry hall as in the current version, but also a far away room in the back for each color. You would have to either be okay with the front spawns, or plan a little adventure: eat food first, and then embark on the journey to the cellar of green color.
As your post-mortem says, you have many cool ideas to expand your game. I guess it is somewhat usual that people really love their first finished LD project and try to expand on it. I did so myself (note that this is a shared Jam account, so you can't find my real first [solo & compo] entry), and it definitely became my finest work as of now. Yet I stopped because there is not really a platform that will give you as much feedback as this LD. I do not know if this is supposed to be a warning, but I thought I would just let you know.
Anyway, I am going off-track. To sum it up: Nice presentation, but the gameplay itself needs to be tweaked.