Try to remember that Aldebaran is the orange star in the right eye of the bull and Alnath is the bluish-white star at the tip of his left horn. Stars are balls of gas with a nuclear furnace at the center. Eventually that energy reaches the surface of the star and heats it. The starlight that we actually see is really the light given off by the surface of the star. It's important to understand that there is a big difference in the physics between the center and the surface of a star.
Energy is created at the star's center.
Next month I will tell you all about that physics. For now all you need to know is that the center of a star is incredibly hot. As that energy works towards the surface it spreads out and cools so the star's surface is much cooler than its core. A star's surface temperature is measured in thousands of degrees - a lot cooler. Stars have different colors because they have different surface temperatures .