This level is relatively easily accessible to people who use psychedelic drugs such as LSD, and appears to be what most people refer to as colourful visuals.
However, it is also accessible to people involved in deep concentration for long periods of time. When lying down at night and closing the eyes, right before sleep the complex motion of these patterns can become directly visible without any great effort thanks to hypnagogic hallucination. The patterns themselves might resemble fractals.