Canan Hastik of the MEGA Museum of Electronics Games and Art released an excellent article on the analysis and classification of demos. It contains the example analysis of the VCS demos Stella Lives! and Beam Racer. It yielded, for example, that BeamRacer ".. shows a massive presence of so-called "coder colors", meaning the programmer of the demo probably chose the colour scheme and visuals himself instead of relying on a graphics artist. This often results in very colourful screens using the whole RGB spectrum." And as the coder, I can confirm that this is true :-)  You can read the full article on Widescreen.

From http://widerscreen.fi/assets/hastik-demoage-06.png From http://widerscreen.fi/assets/hastik-demoage-07.png