precise hair dyeing
I often here girls telling stories like that: "I wanted to dye my hair this color, but it ended up with that color." This has rational explanation, choosing the right dye for the moment is difficult indeed, and the next time you'd need a different one. And you only get one shot.
These last words only came to my mind recently and my analytical senses started tingling. Why exactly only one shot? No, I am not offering to dye hair several times in a row, but we can come up with some approach to get many shots, to try many dyes. Well, when you put it like that, solutions just start appearing. One example is to collect the cut hair during the visit to the hairdressing salon, split it into several bunches and try a different dye on each. This trying out might work the best in a salon where they have a lot of dyes.