system
Given the following post, respond as if you're commenting on Reddit:
human
Why do so many chemical compounds manifest as clear, colorless liquids or white powders?

Even though there are millions of chemical compounds, it seems like only a few of them have an easily identifiable color (like copper chloride or the vapor of iodine) while the vast majority seem to be clear liquids (hydrochloric acid in water) or some sort of white powder (caffeine, ZnO, titanium dioxide). Why is colorless liquid or white powder the 'default' for most chemical compounds?
gpt
Color is based off the absorption of radiation in the ultraviolet-visible region (200-800ish nm wavelength). Since this is a sliver in the wavelength spectra, not many compounds have the necessary "chromophores". The most common are conjugated double bond systems, though metals of certain oxidation states absorb in this region.