Research shows that it, in fact, can affect a person’s mood. Many reasons have been proposed as to why and how colours affect our moods. We react differently to different colours, without even realizing it. This reaction is known to be innate – built-in within each one of us, and not something that is done wishfully or in complete consciousness. For instance, looking at anything in the colour red causes your heartbeat to increase. This is because it is a stimulating colour.