Darkness and the colour black have many negative connotations in our language and culture. Most of the symbolism associated with it is concerned with death, depression, disease and things of an evil nature.
However, in Chinese culture it is linked with yin, the feminine principle, in ancient Egypt with rebirth and resurrection, and in heraldry it is associated with prudence and wisdom – so it is not always negative!
As a child I remember looking at the night sky in wonder, as the thousands of stars twinkled against the dark canopy behind them. Today there is so much light pollution from our cities and towns with street lights and floodlit buildings that very few stars can be seen at night.
So I suppose you could say that we need both darkness and light, that there is a relationship between the two. As it says in Isaiah, 45, 7: “I form the light, and create darkness…” also it is said that 96% of the universe is made of ‘dark matter’.