I think this is my favorite reference, the guy who sings a rock song highlights the word witness because of the style of performance. Also, the location is made in the same graphics as the game, when I first went in I did not understand what was wrong with the graphics, but then the first solved riddle and the pleasant semi-anxious victory music pushed me to the idea that this is a reference to witness, and as you understand, the next riddle confirmed this, an exact copy of one of the riddles from witness. I think this is the best reference, and what do you think?
I saw the puzzle with the different colors and got scared because I thought I was going to have to separate them and stuff, but was relieved when I realized I didn’t have to.