Thermal Radiation Behavior of Non-Black Bodies: I'm Confused!

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Non-black bodies do not emit thermal radiation in the same manner as black bodies, leading to variations in color and spectral intensity. While temperature influences color, the material's composition also affects the emitted spectrum, as seen in phenomena like the blue flame of a torch. The emission of thermal radiation is directly related to absorption; a body at temperature T emits and absorbs equal amounts of radiation at each wavelength. Gray bodies emit a constant fraction of the intensity of a perfect black body across wavelengths. Understanding these principles clarifies the complexities of thermal radiation behavior.
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Hello, I've searched a bit about about the thermal radiation behavior of non-black body and I'm confused.
I've read that the color is dependent only on the temperature so every thing display the same color as a black body.
But at the same time I've read that materials don't always follow the spectrum of a black body.

I've also read that composition plays no role in the color output however the blue flame of a blowing torch is due to the chemicals in the gas and not that it is as hot as a blue star.

I'm confused :frown:

Surely I'm not the only one asking that but I did not found a satisfying answer ( or did not use the wight words for searching )

Thanks for the help and nice week!
 
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Non-black bodies do not necessarily emit the same color or spectral intensity as a black body.
However the amount of every wavelength in every direction of thermal radiation emitted by a body at temperature T, black or not, is equal to the corresponding amount that the body absorbs.
If the body emits a constant (over wavelength) fraction of the intensity of a perfect black it is usually called a gray body.
I believe wikipedia does a pretty good job on this subject.
 
Thanks I think I got it.
 
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