We know that our eyes lie to us: the Mandela effect, optical illusions, or the infamous Blue-Black White-Gold internet dress sensation are three out of countless examples. But did you know that scientists are lying to your eyes, too?

The colors we see are just a small fraction of the total wavelength spectrum that exists. Different wavelengths have different properties: infrared, for example, can pass through dust clouds and detect heat. UV rays are emitted by supernova remnants, but are hard to detect from Earth since our atmosphere absorbs most of them. Matter falling into black holes can be studied using X-rays. All three of these wavelengths are outside our visible spectrum – how much information about our galaxy would we be losing if we had to rely only on our eyes? This is where space imaging equipment comes in. Measurements read and recorded by space telescopes, probes, and rovers often lie outside our visible spectrum. 

But how do we interpret something that we can’t see? 

False color imaging is a group of color rendering techniques that make the invisible visible. Scientists assign a different color to each wavelength, which creates a visual image that can be more easily interpreted by us. Shorter wavelengths are colored blue, while longer wavelengths are often assigned red hues. To highlight distinct features of the phenomenon being observed, scientists may also create higher contrast in specific areas. Stars, explosions, and overall hotter regions are often colored brighter than their cooler surroundings. 

While it may sound like scientists have some sort of “artistic freedom” when deciding how to shape the public’s perception of black holes, supernovae, and even exoplanets, the opposite is the case. False color imaging is a scientific visualization technique, not an artistic choice. Colors are assigned systematically, to ensure that the real data is still represented – although the object may not look the way it does in real life. This way, the images can convey meaningful information and be used for astronomy data analysis. Objectivity is key, so the colors are never chosen due to personal preference, which ensures consistency across a specific scientific field. 

So while the beauty of images taken by Hubble or James Webb is still “there” in real life, you just wouldn’t be able to see it. 

Color doesn’t only lie to you in the field of astronomy. When have you last been to a museum of prehistoric history? Dinosaur models are big, a little bit scary, and more often than not, very green. If you are the type of person to read the labels next to exhibits, you may have learned that birds are the only dinosaurs that survived until the 21st century. Some birds, however, are known to be some of the most visually vibrant species in the world. How is it possible that their ancestor is the brownish-greenish dinosaur? Maybe because dinosaur colors are (mostly) made up. Bones fossilize and are preserved for thousands of years, which is how we know what their body structure looks like. Feathers, fur, and skin, important color markers, are not. Additionally, it is also important to think about why animals have patterns or flamboyant feathers in the first place. Whether this be due to mating, camouflage, or communication within their social group, many shades are linked to the animal’s behavior. Since it’s impossible for us to know what dinosaurs’ customs would have been, we lose this crucial information about their appearance. Scientists often choose to depict dinosaurs as green due to their similarity to modern reptiles, such as lizards or crocodiles. The emerging field of paleocolor aims to explore the real appearances of ancient creatures, using techniques such as studying the chemical signatures of different pigments. 

Adding color to the invisible or unknown helps us understand the world around us. Astronomy and paleontology often have to rely on depicting abstract objects in an accessible manner. Whether it’s visualizing distant galaxies or making ancient creatures come to life, our eyes play a paramount role in how we experience the world around us. Color, in this sense, is not just a decoration – it is a tool to help us comprehend the beauty and complexity of our universe.