Cosmetics Formulation Development

I'm sorry to bother you. Now I'm making hair dye cream. (Conditioner form) with herbal powder mixed with dye SemiColor - Red Brown, I bought this product before the new year. Before the new year, I've seen information about this product on the web. "This dye should be used at a pH of 8.0-9.0 or higher. It will make the color adhere well to the hair." But now I look again and say "should use a pH of about 6.0". What is the pH of the cream to make the dye stick to the hair well? I've also tried making a cream with a pH of around 8-9. I tried adding 2g (2%) of the dye to the 100g (100%) cream recipe. If the range is about 8-9, it is moderately addictive. Not very dark which I would like to have a darker color. So I want to know what should I do.

Hello for SemiColor - Red Brown pH in the range of 8-9 can be done. In fact, between 6-9 can do all, but because the company sells more colors (black SemiColor - Black ), which black itself is not suitable for Using a pH in the 8-9 range, the team decided to align all the data, suggesting the pH of formula 6, at this level. will be available in all colors because there is a chance that the user May consider mixing several colors together (this pH 6 level is reserved for future colours). which plans to import red, blue or other bright colors too) should be used with ColorFix which will help the color adhere better. which can reduce the rate of color usage as well to save paint costs

Thank you very much