Spectra光譜
Heat anything enough and it glows; heat it more and the glow walks from ember to daylight. Drag the slider from tungsten to overcast noon, read the curve Wien draws, and keep in mind that the colour on screen is a translation, not the thing itself.
Blackbody controls
Colour temperature answers one question: how hot must an ideal absorber — a blackbody — be to glow this colour? Wien’s displacement law does the arithmetic: the peak wavelength times the temperature is always about 2.898 × 10⁻⁷ metre-kelvin, so heating simply slides the peak toward the blue. A tungsten filament at 3000 K peaks deep in the infrared and shows us orange; the sun near 5800 K peaks at roughly 500 nm, inside the visible band, and we call the residue white.
Screens and flames disagree because they are not the same kind of object. A flame is a broadband thermal emitter, roughly blackbody, with green-blue chemiluminescence from excited molecules layered on top. An LED or OLED is a narrow set of phosphor or dye peaks that the eye is talked into reading as a temperature — a correlated temperature, matched in appearance only. Two lights can share a number on a box and be physically unrelated.
The translation to sRGB is an approximation and this page says so plainly. The piecewise formula behind the slider fits a smooth curve through chromaticity space and then squeezes it into three channels; a real blackbody spectrum projected onto the sRGB primaries lands slightly elsewhere, and outside roughly 2000 K to 10000 K it drifts further. Use the numbers to compare, not to specify. If a colour has to survive contact with a factory, measure it.