As an expert in astrophysics, I can tell you that the "coolest" color of a star is a bit of a misnomer because it's not about the temperature in the way we typically think of it. In astronomy, the color of a star is determined by its surface temperature, and it follows the principle that the hotter a star is, the bluer it appears, and the cooler it is, the redder it appears.

The coolest stars we know of are red dwarfs, which have surface temperatures ranging from about 2,300 to 3,800 Kelvin (2,000 to 3,500 degrees Celsius or 3,600 to 6,300 degrees Fahrenheit). These stars are much cooler than our Sun, which has a surface temperature of about 5,500 Kelvin (5,200 degrees Celsius or 9,400 degrees Fahrenheit). However, it's important to note that "cool" in this context is still very hot by everyday standards!

So, to answer your question, the coolest color of a star is red.

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Our Sun is a type G star, which are yellow stars with surface temperatures of about 6000 ��C, or 11,000 ��F. Type A stars, which are hotter, are white in color and maintain temperatures of around 10,000 ��C or 18,000 ��F. The hottest of the types, B and O, are blue stars while the coolest of type M are red in color and ...read more >>