Final answer:
The Sun is a medium temperature star with a surface temperature of about 5800 K, which is hotter than M type stars and cooler than O type stars. It appears yellowish from Earth due to scattering of blue light by the atmosphere.
Step-by-step explanation:
Based on the Balmer thermometer and other assessments of stellar temperatures, the Sun is considered a medium temperature star. The Sun falls into the spectral class of type G stars with a surface temperature of approximately 5800 K, which is cooler than the hottest stars of type O, that can exceed 40,000 K, and hotter than the coolest M type stars, which can have temperatures around 2000 K.
When comparing the Sun's temperature to the hottest and coolest stars, we find it falls in a middle range. Moreover, the Sun experiences some color changes due to the scattering of blue light by Earth's atmosphere, which leaves behind longer wavelength lights like red and yellow, making the Sun appear somewhat yellowish from Earth's surface.