Pink Platinum can only be used when the hair is showing a brassy tone, as it is ultimately an anti-yellow neutraliser. So, when the hair starts looking brassy, you apply it. However, because Pink Platinum has that additional pink molecule, you may find that rather than the hair becoming brassy over several washes, it starts taking on more and more of a Rose Gold appearance and will at one point look very much like the Colour Restore Candy shade. This happens because the pink molecule will start to combine with the underlying yellow molecule and create a Rose Gold tone. However, very quickly, this Rose Gold tone will fade to a clear brass, indicating the entire Pink Platinum tone is now gone. Therefore, if you apply the Pink Platinum when the hair is becoming more Rose Gold than pink – you would get a good pink platinum result, as there is sufficient underlying yellow displaying in the hair to utilise all the acid-violet pigment.