yes
No.
To make 10 volume developer from 20 volume developer, you can mix equal parts of 20 volume developer and distilled water. For example, mix 1 part of 20 volume developer with 1 part distilled water to create 10 volume developer.
To achieve a 30 volume developer solution, you can mix equal parts of a 20 volume developer and a 40 volume developer. This will result in a 30 volume developer solution.
Equal parts of 5 volume developer + 15 volume will yield approximately 10 volume.
No, diluting a 30 vol hair developer with water will not change the volume strength of the developer. To make a 20 vol developer, you would need to mix the 30 vol developer with a neutralizing solution or a lower volume developer.
20 volume
You have to have a actuall hair color to mix with it. Use 2oz of the color and 4oz of the developer and mix. And apply to your hair
To make a 40-volume developer, you would mix equal parts of 20-volume (6%) hydrogen peroxide cream developer with another equal part of 20-volume (6%) hydrogen peroxide cream developer. This will give you a total volume of 40 (12%).
Mix equal parts of developer and Wella color.
To create a 30 volume developer solution with a 40 and 30 volume developer, you can mix equal parts of each developer together. For example, mix 1 part 40 volume developer with 1 part 30 volume developer. This will result in a 35 volume developer solution, which is close to 30 volume. It is important to perform a strand test before using the mixed developer on your hair to ensure it is the desired strength.
Every company has a different quantity of peroxide that they mix with their colours. You will need to find that out.