If your brain was the same, probably yeah it would stretch.
It would definitely stretch if the only change was that your 2 of your 3 cones changed to detect higher and lower frequencies, and the 3rd just widened - you'd have only one cone dedicated to the narrow spectrum that most people have 3 to detect, so anything that only emits our human-visible light would be nearly monochromatic.
Who knows which color it would land on, but yeah it would definitely be monochromatic if an object wasn't warm, wasn't UV reflective, wasn't a radio, etc., you'd see it as monochromatic.
If your brain was the same, probably yeah it would stretch.
It would definitely stretch if the only change was that your 2 of your 3 cones changed to detect higher and lower frequencies, and the 3rd just widened - you'd have only one cone dedicated to the narrow spectrum that most people have 3 to detect, so anything that only emits our human-visible light would be nearly monochromatic.
Who knows which color it would land on, but yeah it would definitely be monochromatic if an object wasn't warm, wasn't UV reflective, wasn't a radio, etc., you'd see it as monochromatic.