The world of food colorants has experienced a very exciting development in the last few years. The demand for increasingly organoleptic appealing, a safer, secure and healthy foodstuff is evident for consumers. Among them, the health-promoting ability of food products containing colouring agents is considered the most important. Linked with this, natural food colorants have been proposed as the most promising and safe alternatives. Numerous side effects and related toxicity have been increasingly associated with the consumption of synthetic colorants, some being already forbidden, while for others, the adequate daily intake (ADI) was re-adjusted. Thus, the aim of the present chapter is to provide an overview on the field of food colouring agents, namely highlighting the currently available natural and synthetic sources of colouring agents, the main representative groups and corresponding physicochemical properties, legislation and regulatory practices, and finally the latest pharmacokinetic data.Phenolic compounds, including anthocyanins, carotenoids, and betalains, comprise the most commonly used food colouring agents from natural origin. At the same time, increasingly strict regulatory practices have been applied for the quality assurance of those from natural and synthetic origins. Naturally-derived food colorants seem to have higher quality and efficiency than those from synthetic sources, apart from playing a significant role as health promoters. Concerning synthetic food colorants, due to the increase in the reported side effects and toxicity, they have been progressively substituted by those obtained from natural origin. Allergic reactions, behavioral and neurocognitive effects are among the most frequent side effects, both at medium and long-terms. Overall, a marked change in attitude and priorities has been observed in consumers, not only related to food and nutrition science, but also pharmaceutical, nutraceutical and cosmetic industries. It drives manufacturers to find new, natural and healthy sources of colors and flavors and other organoleptic attributes for the currently marketed food products.