Though people have used many different substances to create dye throughout history, modern dyes are usually made from chemicals.
Most dyes are derived from chemicals that come from petroleum or coal. However, there are some dyes made from natural substances or a mix of natural and chemical substances.
While people used to use the indigo plant to dye clothes, indigo dye today comes from a mixture of caustic soda, sodium phenylglycinate and sodamide.
Modern dyes are derived from petroleum and coal because they are cheaper and easier to obtain than the plants and animal substances traditionally used to make dye.
Natural dyes, derived from plants and insects, are gaining popularity because they have a less negative impact on the environment.
All dyes, whether natural or chemical, must be proven safe for human use before they are approved for use.