How do you start the color square puzzle?
Make sure you complete the escape room (and can leave) - when clicking the exit, decline to exit and click the left arrow instead
I've completed the room, and chosen to 'Stay', but nothing will activate in the color square puzzle.
Right after you choose to stay, you can click the "left arrow" navigation at the bottom right of the screen. Clicking the left arrow will bring you to the scroll which starts the color puzzle.