Researchers from the University of Leeds have published their findings about a patented technology which enables the pigment to be extracted from blackcurrant waste to provide an intense semi-permanent hair colour product. You can read more details at http://www.bbc.co.uk/news/uk-england-leeds-44303626 or read the original research arcticle available in Journal of Agricultural and Food Chemistry at https://pubs.acs.org/doi/10.1021/acs.jafc.8b01044