A star is five times as luminous as the Sun and has a surface temperature of 98,000 K. What is its radius, compared to that of the Sun?
Color of a star is directly related to it's temperature. Yellow stars like our sun are in the range of about 5000-6000 degrees C. Orange stars like the Supergiant Betelgeuse have a temperature lower than the main sequence stars of about 3000-4000 degrees C. However, the Blue stars which have temperatures above 10000 degrees C are the hottest stars. But if a star is about 98000 k it must be really luminous compared to our sun.
The star R136a1 in the constellation Dorado has a temperature of about 53000 degrees C, it is a Blue Hypergiant and it's luminosity is about 9 million times than of our Sun.