The color of a star with the lowest temperature is red.

Here's why:

* Star Color and Temperature: A star's color is directly related to its surface temperature.

* Hotter Stars are Bluer: The hottest stars emit more blue light, making them appear bluish-white.

* Cooler Stars are Redder: The coolest stars emit more red light, making them appear red.

While there are different shades of red, the stars with the lowest temperatures are often referred to as red dwarfs. These stars are much cooler than our Sun and are very faint.