A neutral colour, grey is mostly seen as dull and dismal – quite often like some of our weather – and has been linked to poor self-esteem and indecisiveness. Sometimes grey can appear warm and at other times cold and hard, mostly because it is rarely pure and tends to be affected by another colour.
Culturally grey has come to signify notions of inertia, dullness, lack of imagination, tiredness, depression, confusion, indifference and being very conventional, in short, all fairly negative qualities.
In Astrology it is linked to the planet Mercury and so with mentality and intelligence; in heraldry with tribulation; in Judaism with wisdom; in Christianity with renunciation, death of the body and immortality.