The main pigments used were chemically-stable mineral oxides, and charcoal and bone-char. They're unaffected by the usual enemies of pigments: oxygen, moisture, and sunlight. The main colours used are:

• reds: iron oxide (hematite)

• yellows: iron oxide (goethite)

• blacks: manganese oxide, charcoal, bone-char

• brown: usually mixtures of iron oxides and manganese oxides

• whites: kaolin, calcium carbonate, zinc oxide

Many cave paintings are limited to these colours:

• https://commons.wikimedia.org/wiki/File:SantaCruz-CuevaManos-P2210651b.jpg

• https://commons.wikimedia.org/wiki/File:Rhinos_Chauvet_Cave.jpg

• https://commons.wikimedia.org/wiki/File:(1)Jabiru_dreaming-7.jpg

• https://commons.wikimedia.org/wiki/File:Serra_da_Capivara_-_Several_Paintings_2b.jpg

and many use only one colour:

• https://commons.wikimedia.org/wiki/File:Lubang_Jeriji_Sal%C3%A9h_cave_painting_of_Bull.jpg

Blue pigments appear in some American and African paintings:

• https://commons.wikimedia.org/wiki/File:Seminole_Canyon_Park5.JPG

• https://commons.wikimedia.org/wiki/File:2009_07_09_camino_cielo_paradise_137.jpg

but are very rare in Eurasia.

Some pigments were mined and traded over long distances. The iron oxides used in the Lascaux paintings might have come from 40km away, and the manganese oxides 250km. Some pigments were deliberately modified, e.g., by heating to convert hydrated oxides to anhydrous oxides.

Chemically-stable pigments is an important part of the story, but not the whole story. The pigments need to stick to the rock, and to stay stuck to the rock. The cave paintings that have survived are generally in protected locations, where rain or other water will not wash the pigments away, and the painting is protected from sandy winds. Sometimes, the rough surface of the rock is the main thing causing the pigments to stick - if a piece of the mineral or a piece of charcoal is rubbed on the rock, it will leave a streak like chalk on a blackboard. Sometimes, a binder is used - the main binders appear to have been saliva, fats, blood, and plant sap.

There are other types of rock art, which can survive in more exposed locations. These are typically made by pecking away a coloured patina on the surface of the rock, exposed the uncoloured rock below:

• https://commons.wikimedia.org/wiki/File:Negev_camel_petroglyph.jpg

• https://commons.wikimedia.org/wiki/File:Golpayegan.petroglyphs0101.jpg

or by deeply engraving the rock:

• https://commons.wikimedia.org/wiki/File:Libya_5321_Meercatze_(Gatti_Mammoni)_Petroglyphs_Wadi_Methkandoush_Luca_Galuzzi_2007.jpg

• https://commons.wikimedia.org/wiki/File:Laxe_dos_carballos_01.JPG

These will eventually be destroyed by weathering of the rock, but can last for a long time, even if exposed to the elements.