For the same type of reason there are colors here on Earth. That's because different substances react differently to light.
To hide from predator planets.
Yes. Planets and moons come in all sizes and colors.
It depends on the particular planet.
nitrogen oxide
Pluto has the main colors of brown, blue, and some yellow. All these colors are mixed in various parts of the planets.
Substance that made up it's surface
by how far they are from the sun or their condition in space
They all are different colors
It changes by the storms and wind in the planets atmosphere
We do not know. Although we have detected planets in other solar systems, we do not know what colors they are.
Neptune and Uranus are blueish because of methane gas.
Planets have their colors because of the materials on their surface. For example, Mars appears red due to iron oxide, while Neptune has a blue tint because of methane in its atmosphere. The varying compositions of each planet determine their distinct colors.