it doesn't matter.
Haircolor Level
i have the loreal technique preference permanent haircolor "natural black #3" and i dont know how much of 20 volume creme to mix it with.
It must be distilled water but yes. You can combine equal parts distilled water and 40 volume to get 20 volume developer.
Grey
Yes why not?
The density of the substance is needed to convert mass to volume in a stoichiometry problem. Density is a measure of how much mass is contained in a given volume. It relates the mass of a substance to its volume.
Not much. Of course, the exact amount of energy varies, depending on the sound volume.
The volume of the developer simply tells you how many levels it will lift your hair so since you are using 30 volume, it will lift your natural color 3 levels higher to help the permanent color show better. The volume/color ratio is 1:1 which means however many oz. of haircolor you use, you put the same number of oz of developer. For example: 2oz permanent haircolor: 2oz of developer I hope this helps you! Source: I am a cosmetologist
brunett
brown
To determine the amount of water needed for 500 ml of juice with a ratio of 1.4 (juice to water), you can use the formula: juice volume = ratio × water volume. Rearranging this gives you water volume = juice volume / ratio. Therefore, for 500 ml of juice, the water needed would be 500 ml / 1.4, which is approximately 357.14 ml.
dark brown/black