“…there might be in nature other colors than those we know in our world. “
Who was the first known person to speculate that there might be colors beyond that which we can see?
So far, it appears to be Emilie du Châtelet, in 1737.
She speculated, through experiment and logic, that light carries heat yet that light is separate from heat (she talks about fire) and gives the idea for Herschel’s experiment in 1800 that confirmed that infrared exists just beyond the rainbow of measuring light with thermometers.
She also writes:
The light of the Sun appears to be close to yellow, this means that the Sun must, by its nature, project more yellow rays than rays of other colors,
It is very possible that in other systems there may be Suns which, projecting more red, green rays, etc. than the basic colors of the Sun that we do see, might be different from ours, and that, lastly there might be in nature other colors than those we know in our world.
-Emile Du Chatelet, 1737, “Dissertation on the Nature and Propagation of Fire”