Blue means hot
Rigel's color comes from its high surface temperature. It is much hotter than Betelgeuse, so it emits strong blue-white and ultraviolet light.
Its radius is far smaller than the largest red supergiants, but it remains extremely luminous.
A useful Orion comparison
Orion gives a visible lesson: red Betelgeuse and blue-white Rigel sit in the same constellation but represent different supergiant conditions.
That comparison is one of the strongest beginner hooks for this topic.
What comes later
Like other massive evolved stars, Rigel's future depends on mass loss and internal evolution. A core-collapse ending is expected for stars in this mass range.