1. of a neutral tone, intermediate between black and white, that has nohue and reflects
and transmits only a little light
2. greyish in colour or having parts or marks that are greyish
3. dismal or dark, esp from lack of light; gloomy
With my hair I go through phases and I like to change the colour of it all the time. I have been purple fading into a soft pink for the last 6 months and now I wanted to go back to a white blonde colour but with grey / silver ombre feel to it. So here is a mood board with some ideas - the bottom right is by far my favourite.