Pigments are passive (often solid-state) colorants used in everything from the shells of marine creatures to the hulls of spacecraft.
While Optical Phased Array and quantum well programmable matter technologies long ago replaced passive pigments in many applications, they are employed where energy savings, durability, personal preference, or other factors influence.
Pigments can be divided into two main types: structural and chemical.
Structural pigments derive their optical properties from their micro/nano structures which reflect and absorb, interfere with, or diffract incident light.
They are the most common type of pigment because their optical properties don't depend upon chemical composition, and can therefore be engineered from a wide variety of materials--they may be chemically stable, achieve colors that would otherwise require programmable matter* to produce, or be environmentally degradable.
Nickel-copper alloys, gold, and the platinum group metals are formed into exceptionally stable structural pigments which are not degraded by the action of ultraviolet light or oxidation.
Any solid color from the spectrum can be produced with structural pigments, as well as some effects not possible with strictly chemical pigments, like iridescence and virtually non-reflective ultra-blacks.
Some structural pigments are nanomechanical in nature, their properties can be retuned, requiring no maintenance energy between resets.
Chemical pigment technology has changed little over the millennia. Many modern colorant compounds would be familiar to Information Age Old Earth. Many of them are absolutely light-fast and have low chemical reactivity. Titanium dioxide still provides one of the purest whites, and is self-cleaning under ultraviolet illumination. Mars black (Fe3O4) is still one of the deepest, most chemically durable blacks. And Subramanian blue is still one of the most vivid, durable blues.
Pigments manufactured from a combination of organic dyes and palygorskite (or similar clays) are particularly durable, withstanding millennia of exposure to harsh environmental conditions.
*Quantum well programmable matter cannot be hardened against ionizing radiation without encasing it in shielding materials such as lead, which precludes its use as a colorant in high-rad environments.