I have just done my mums regrowth she's 90% grey and I normally use wella 66/46 and 66/0 equal parts but this time I used igora royal 6-88 and 6-0 equal parts with 6% and her roots are really glowing is it the colour or is it because I used generic peroxide which was almost empty , I was going to buy a fresh bottle of igora 6% but none of my wholesalers had any in stock and didn't have time to order online