Tachran was a small planet in the Outer Rim, home to the Tachrani people. It had very little light, and most of the native plants had evolved to create food through a combination of thermosynthesis and photosynthesis, as there was not enough sunlight for them to make sugars through photosynthesis alone, even though the plants could make 10 times the amount of sugar through photosynthesis that plants on brighter worlds could.
Most animals, including the sentient Tachrani, had visual ability well into the infrared range, with less ability to see in the normal light spectrum. Violets and blues showed in grayscale, and the ability to wavelengths corresponding to red through green varied by species. As a result, most life evolved to eliminate color, and the entire world, even when illuminated, was mostly black, white, and shades of gray, with occasional muted reds and yellows. The only exceptions to this were naturally occurring chemical compounds that inherently reflected higher wavelengths; these objects were perceived to the native population as gray, but visitors from other worlds could see them in their true colors.