We can see if it is just pedantry at work, or ego, lust, therapy or confession. We can also see if it is something more, deeper, about larger truths, touching a live nerve. We can see if it is emotional, psychological, spiritual, sensual or thoughtful in its primary sense. We can see if the individual was in awe of paper or not even aware of it. Light is how we see, and in its absence we don't.
All works are therefore, to some degree or other, about light.
Works on paper seem especially blessed in this respect since they are washed in the pure paper light, and they never forget it. There are even individuals who devote themselves entirely to this light, and only seek to magnify it. We face their works as we face the sun and stars. Color is one of the joys of light, and of living. It is often how we know things and enjoy them.