Pro level stuff! :)
Those bumpers are nasty as hell.
There's a glitch in dialogue triggering in the tutorial. I went very fast and some dialogue was displayed too late. I managed to enter the small room with yellow lights, pick up the lights and paint the room without any dialogue. Then I painted the whole level but exit door didn't appear. I accidentally discovered that I need to enter the yellow lights room again to trigger the dialogue. After that the door appeared and I could progress.