Hair colour refers to the process of changing or enhancing the natural colour of the hair using dyes or colorants. It can be done to cover grey hair, create a new look, or add highlights or lowlights for dimension. Hair colour options range from natural shades to bold and vibrant colours, allowing for customization and personal style expression. It is important to consult with a professional stylist to choose the right hair colour and ensure proper application and maintenance for desired results. Regular touch-ups may be necessary to maintain the colour and prevent noticeable regrowth.