HeyCurls clip-in hair extensions can be straightened and coloured. However, please bear in mind that, just with your own hair, when not done correctly you can damage the natural hair extensions. Colouring your hair extensions may weaken the hair strands and alter the curl pattern. We recommend going to a professional colourist / hair stylist that is familiar with colouring curly and kinky hair. HeyCurls extensions are steam processed to create each curl pattern. Lifting the hair with high volumes of developer to extremely light colours can damage the hair strands. Colouring is always done at the discretion of the customer. HeyCurls cannot be held responsible for any damage done to the hair texture as a result of colouring.