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Most of the material when heated turn red or orange or yellow, why materials don't have a tone green or blue when heated high.

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marked as duplicate by StephenG, Sebastian Riese, Kyle Kanos, stafusa, Jon Custer May 23 '18 at 19:41

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At temperatures of around of 1000K any material looks reddish.

The spectrum of light emitted by a hot material is roughly proportional to the temperature. It is virtually the same for any material and the phenomenon is known as black body radiation. Black in this case means that reflected light is not included. If the temperature of a material is increased then the spectrum shifts to higher frequency. For a piece of iron of 1000K most radiation is emitted in the infrared, which we feel but cannot see. What we do see is the high frequency, red tail of the spectrum. If we turn up the heat the colour shifts via orange to yellow at 5500K. Between 6000K and 6500K it shifts from green to blue.

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This is really a 2 part question. One, is the physics of black body radiation per @my2cts, with a caveat for emissivity--which is a material dependent deviation from back body radiation.

The other is human vision, and is best described by the CIE color space: enter image description here

The curved boundary with blue numbers (wavelength in nanometers) are the monochromatic colors. Any mixed color point inside figure can me made by an infinite number of binary mixture of 2 wavelengths which are given by drawing a straight line through the point that intersects the wavelength boundary at 2 points. Those 2 wavelengths are then mixed in contra-proportions to length of the chord joining the point. (This is for the average human eye).

The solid line with temperature in Kelvin is an average of the black body spectrum showing that it "turns on" in pure red, moves on to orange, yellow, white, and then finally blue for things like arc welders, lightning, and blackhole accretion disks.

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