Planetary color can be highly subjective. The human eye is less sensitive to color in faintly lit environments. This is of particular importance when processing images of Uranus, or Neptune, where the sunshine is almost 1,000 times fainter than it is on Earth.

The Voyager 2 spacecraft flew by Uranus and Neptune in 1986 and 1989, respectively. Compared to modern spacecraft, the color data from Voyager 2 is of relatively low quality. However, it is possible to use the visible light spectrum of Uranus and Neptune to compute their average global color and then use this to correct the color of the Voyager 2 images. The color of Uranus and Neptune is similar, but not identical. Uranus appears greener and Neptune bluer.