Political colour which dates back to the French Revolution in the 18th century and the revolutions of 1848. Before this nascence, the colour red was generally associated with monarchy or the Church due to the symbolism and association of Christ's blood. The colour red was chosen to represent the blood of the workers who died in the struggle against capitalism. All major socialist and communist alliances and organisations—including the First, Second and Third Internationals—used red as their official colour. The association between the colour red and communism is particularly strong. Communists use red much more often and more extensively than other ideologies
Colour centre the recognition of shapes, motion, and colour. V1 has multiple areas that are colour-sensitive, which indicates that colour processing is not limited to one area. According to a paper by Dr Robert Shapley, V1 has an important role in colour perception. fMRI experimental results showed that V1 has two kinds of colour sensitive neurons: single-opponent and double-opponent cells. These cells are integral in the opponent process of interpreting colour signals. Single-opponent neurons respond to large areas of colour. This is advantageous for recognizing large colour scenes and atmospheres. In comparison, double opponent cells respond to patterns, textures, and colour boundaries.