Hey! Thanks for playing. The Blue Ninja is actually the NPC who gives you the solution to the light puzzle. It's not a hard lock, after speaking with them, you need to set the lights according to their hint, and then a hidden path will open in the previous room on the left.
I know it's confusing because there's no audio or visual feedback when you solve it correctly, that's definitely something I should have added! My apologies for the confusion. Let me know if you're still stuck!
