Most exoplanet pictures are artists' impressions, made to inspire rather than to measure. This site is the other half of the story: the colour physics predicts for each of 5,785 real exoplanets, computed, never photographed, and labelled with exactly where the model ends.
For every known exoplanet, this site models the light the planet reflects, multiplies it by its host star's light, and passes the result through the same colour-matching maths your eye performs. Out comes the colour a human would see. Methane makes a world blue-green; thick cloud pushes it toward white; a cloud-free hot Jupiter comes out nearly black. Each planet is also shown as the Nancy Grace Roman Space Telescope's coronagraph would record it, so you can see how much colour identity survives a real instrument.
These are computed colours, models rather than photographs, and every page says so. Five solar-system planets run through the identical pipeline from measured spectra as a calibration check: if Jupiter came out wrong, everything else would be wrong too. The full method is on How we get the colours, and every scientific input is credited on Sources & credits.
I'm João (jocarino on GitHub), a software engineer in Portugal. This is a one-person project, built on evenings and weekends, with no funding and no astronomy affiliation: everything here stands on the published work of the scientists credited here, and every claim is checkable against it. I made it because I wanted a version of these colours with the working shown, one you can check assumption by assumption, and that turned out to be a thing worth sharing.
Email joaogveloso.contact@gmail.com, or open an issue on the project's GitHub. Email is answered within a few hours in European daytime (Portugal, UTC+1 in summer). Corrections are especially welcome: if anything here misstates your work or your instrument, I would rather be told than be polite about it.
Writing about this site? Images and information for writing about this has ready-to-publish pictures with captions, credit lines and licences, plus copy you can paste and the facts checked. The short version: the site's own renders are CC BY 4.0. Use them, credit them, and please call the colours what they are: computed, not photographed.