Camouflage colouring was invented by artists for the military around 1900 so soldiers and their vehicles would blend into their backgrounds and therefore be more difficult to spot by the enemy. Warhol began to use camouflage designs for his paintings in 1986. Their all-over, repeating patterns appealed to his interest in abstract expressionist painting. By varying the colours he used, such as bright yellows, reds, pinks, purples and blues, Warhol was able to remove much of the military symbolism of the pattern, yet still retain the idea of hiding. Warhol was known for hiding his true self - he would give short, often one-word answers in interviews and wore a series of wigs and make-up. This was due to feelings of personal insecurities, especially regarding his appearance.