English: What an ammonia world, with an advanced stage of life, may look like.
Rationale for appearance:
The ammonia oceans, if it were just ammonia, would probably appear blue just like water. However unlike water ammonia can dissolve alkaline earth metals as if they were salt. When this happens the color changes. Dilute amounts of metal give it a an intense blue color, slightly higher concentrations give it a gold bronze color as shown here.
The reddish orange color in the atmosphere is due to oxides of nitrogen (nitrogen analogs for oxygen). Like Earth the atmosphere is primarily diatomic nitrogen. Unlike Earth it contains next to no free oxygen, but has nitrogen oxidizers. Most probably nitrous oxide, but it could be nitric oxide. It’s hard for me to figure out which would be more likely.
The planet would be much colder than Earth, so I depicted the vegetation as black to collect more light. Unlike water worlds like Earth, plants on ammonia worlds may not need to deprotonate water (or ammonia) molecules to get an electron for photosynthesis. This is because the dissolved alkaline earth metals release solvated electrons that can be used directly. This could free up photosynthetic plants to use a wider range of the spectrum.
Finally ammonia clouds and ice are white just like those of water.
Also, from the main article, a few pointers on the kind of temperatures & pressures of an ammonia-based biosphere.
A biosphere based on ammonia would likely exist at temperatures or air pressures that are extremely unusual in relation to life on Earth. Life on Earth usually exists within the melting point and boiling point of water at normal pressure, between 0 °C (273 K) and 100 °C (373 K); at normal pressure ammonia’s melting and boiling points are between −78 °C (195 K) and −33 °C (240 K). Chemical reactions generally proceed more slowly at a lower temperature. Therefore, ammonia-based life, if it exists, might metabolize more slowly and evolve more slowly than life on Earth. On the other hand, lower temperatures could also enable living systems to use chemical species that would be too unstable at Earth temperatures to be useful.
Ammonia and ammonia–water mixtures remain liquid at temperatures far below the freezing point of pure water, so such biochemistries might be well suited to planets and moons orbiting outside the water-based habitability zone. Such conditions could exist, for example, under the surface of Saturn‘s largest moon Titan.