Colour 99/0

[Kezzzziiii]

Does anyone know why 99/0 wella colour has gone more like a 8 base when doing my mothers roots.she has 100% grey and she always has 9/0 and it's usually a very light blonde. But this time I thought. I would try a double base. I'm really confused to why it's gone so dark. Can anyone help please

 

[adamlea87]

Double bases have more pigment to help cover on resistant hair textures. If the hair isn't resistant the extra pigment will make the final colour look darker.