Electromagnetic spectrum?

Question

I'm aware that the infrared section in the spectrum lies close to the red light section and sometimes a hot object emits red light which is hot, this makes sense because they both lie close to one another, but why can there be the same red color light that doesn't have any potential of heat?. Does this simply means the object is radiating two different wavelengths?.

Answer 1

In a rainbow or the separation of colors by a prism we see the continuous range of spectral colors (the visible spectrum). A spectral color is composed of a single wavelength and can be correlated with wavelength as shown in the chart below ( a general guide and not a precise statement about color). It is safe enough to say that monochromatic light like the helium-neon laser is red (632 nm) or that the 3-2 transition from the hydrogen spectrum is red ( 656 nm) because they fall in the appropriate wavelength range. But most colored objects give off a range of wavelengths and the characterization of color is much more than the statement of wavelength. Perceived colors can be mapped on a chromaticity diagram.

See below

Answer 2

No, red light is red light is red light.  It's all the same wavelength, but it can come from two completely different phenomena.

Something that is hot radiates in a characteristic spectrum whose color depends on its temperature.  So it can glow infrared or red hot or even white hot if it's super hot.  Some stars are even hot enough to glow blue or even higher frequencies.  Go wiki "blackbody radiation" if you want to see more on that.

Something that is just normally red is that way because of it's chemical composition.  The mollecules in red paint (or anything red) have resonances that preferentially absorb the non-red light and reflect the red.