The colours blue, green and black are the most commonly used in visual communication depicting isolation and loneliness. In the Semantic Colour Space these three primary colours are all located at the back. In the depth dimension this suggests a meaning with a strong focus on the inner world of thought.

The three primaries, in the context of isolation and loneliness, might express the following notions:

blue: corner, distant; space;
green: crossing, barricade;
black: stop, shut-up.

In the context of being alone in a closed space the blue-on-green colour combination, and the semantically associated hue turquoise blue (blue-2), expresses a compelled isolation. In the case of Covid-19 for example, that would be a disciplinary measure imposed on citizens by the government, or self-imposed for fear of contamination. This situation for civilians could metaphorically be described as civilians chained to their homes.

When the emphasis of isolation is placed on the feeling of utter abandonment as a mode of a depressed mental state, the colour-combination black-on-blue and the semantically associated hue dark grey (black-1), is frequently used in visual communication.

In case the isolation is characterized as a trap or imprisonment, the colour combination black-on-green and the semantically associated hue olive drab (black-3) are best suited.

The Semantic Colour Space reveals the close relationship of concepts found in the colours of visual communication expressing loneliness and isolation.

The poster for the film Caged combines different aspects of the idea of loneliness and isolation. The use of turquoise in the background conjures up the notions of chains and forced isolation. This ambiguous hue can be seen as blue-green as well as green-blue. With black in the foreground we can evoke the feeling of being imprisoned (black-on-green), and the presence of an ensuing depressed mental state (black-on-blue).