The colour of a crowd can find it's origin in many different reasons or causes and depends on many parameters as well the perspective of the observer. Colour can be functional, coincidental, esthetical e.g.
Is the perception of colour influenced by a lens, a printing colourformat or colour of light? Or do the single elements from which the crowd is build up dominate in giving the crowd it's colour? The painter will make decisions in a creative process choosing expressive colours or chromatic greys and is determing the colour of the crowdpainting. Here also colour is functional, coincidental or esthetical.