Stuck :< I've blacked out some stuff that I did when using improper logic—I thought the circled tile was safe but it could have been green—but even with that extra information I have no idea what I can deduce next.
Tons of lines are there so you have to click View rest so that there's no spoilers :3
This step requires a bit of trial and error looking a step ahead: You have to consider the different places Red might be centered. All but one will be impossible.
(Hint: Focus on where the U-shaped reflection could go. Only 3 places should seem reasonable. Two of them can be a little tough to rule out and might require some sketching -- but not looking very far ahead.)
