Neptune is an ice giant planet that is blue in color and is the fourth-largest planet in the Solar System. When looking at Neptune with smaller detail, an observer will see the planet's blueness as largely smooth and uniform. When looking with more detail, however, the striations on the planet's surface that are caused by storms in Neptune's atmosphere are more apparent.
While many planets in the Solar System have variations of color and texture on their surfaces, Neptune looks a lot like a smooth blue marble, though some images, such as those from NASA's Voyager spacecraft, show that the planet's blue surface is marked by white and light blue cloud systems, creating round, striped shapes.
In addition to being defined by its blueness, Neptune also has a few characteristic physical features, including what NASA refers to as the Great Dark Spot, which is a storm that creates a darker blue-gray spot on the planet's surface.
Neptune does have rings, but those rings are not typically visible because they're so small. This eighth planet from the Sun also has 13 known moons that accompany it in its orbit. Sometimes described as Uranus' twin, Neptune is the furthest planet from the Sun. It secured this spot after Pluto was reclassified as a dwarf planet in 2006.