The Over The Rainbow team kick off The Colour of ... series with red - the colour of love. It was one of the earliest naturally occurring colorants of course; red ochre. Red ochre was used extensively in cave paintings 60,000 years ago or more. These incredible and ancient works of art remain because of the lack of light in these environments. This contrasts with the statues of Ancient Greece and Rome which were gaudily coloured at their time of creation but have faded over the years to the extent that many people mistakenly believed they were designed to be white! Cochineal was another early colorant, made from the crushed bodies of insects but used widely as a food colorant (it is even still used today). Culturally red can mean many things of course and some reasons for these associations are discussed. The historical basis of the term 'red light district' is also explored. On balance, research seems to show that people are viewed as being more attractive if they wear red. Red may be the colour of love, but does t really make the heart beat faster? Research also points to sporting teams that wear red outperforming teams that wear blue. But why is this?