Mix some violet temporary dye in with your conditioner and use it as a hair mask for 10 minutes or so after shampooing. This will neutralise the drab yellow undertones in your grey and give you tge colour you're after.
You need to use this every time you wash your hair to keep the colour, and bonus your roots will always match.
I don't mind my greys I have quite a few despite only being in my mid thirties.