Brown is a phenomenon in which viewing a dark shade of orange, it is perceived as a different color, mainly perceived when the shade of orange is significantly darker than the area around it.
Brown cannot physically exist as true light, as it is not a product of RGB values, but your eyes being illusioned into seeing it as a different color due to surrounding context. Some people are more sensitive to this illusion than others.
Color theory is a perfect excuse to call “brown” orange, as nothing can actually be brown due to the nature of brown.