Question

Why does Neptune appear blue and Jupiter red?

Answer 1

Generally our eyes, Uranus looks naturally green and Neptune blue, because the tops of their clouds of condensed methane are seen through a great depth of methane gas that filters out the red component of sunlight so that only green-blue light makes it down to the clouds and back out

Answer 2

Neptune's atmosphere is made up of hydrogen, helium and methane. The methane in neptune's upper atmosphere absorbs the red light from the sun but reflects the blue light from the Sun back into space this is why Neptune appears blue whereas the clour of Jupiter changes with storms and wind in the planet's atmosphere. The clours of Jupiter's atmosphere are created when different chemicals reflect the Sun's light.