What sequence of star colors from hottest coolest?

Blue stars are the hottest whilst black dwarfs are the coldest.

(However, no black dwarfs exist yet - see related question)

The stellar classification [See link] in order of temperature. Our Sun is classed as yellow.

• Blue > 30,000 Kelvin
• Blue to blue white 10,000 -> 30,000 Kelvin
• White 7,500 -> 10,000 Kelvin
• Yellowish White 6,000 -> 7,500 Kelvin
• Yellow 5,200 -> 6,000 Kelvin
• Orange 3,700 -> 5,200 Kelvin
• Red 1,000 < 3,700 Kelvin
• Brown < 1,000 Kelvin
• Black 0 Kelvin

See link [Kelvin] for conversion ratiOS.

See link to [Stellar classification]

Hottest Internal Temperature

However, the "hottest" star in the universe is a neutron star, based on its internal heat, which it does not radiate effectively into space. The temperature inside a newly-formed neutron star is around 1000 billion Kelvins. However, the neutrinos that it emits (in massive numbers)carry away so much energy that the temperature falls within a few years to around 1 million kelvins. Most of the radiation generated by a neutron star is X-rays. In visible light, neutron stars probably radiate approximately the same energy in all parts of the visible spectrum, and therefore would appear white.