Temporary colour for white hair

I am going to try a "pearl " toner on Wednesday, it is called Pearlised Milkshake or some such nonsense. I thought steel would look dark and platinum as if I was trying to cover up the grey/white I have been carefully achieving over the last 3 or 4 months, cutting out the old colour at the tips and lightening it where it looks patchy.
Hope I have judged it right!!
(I prefer the prospect of white to grey)

My mum always used Nice N Easy, worked a treat. My hair dresser is using a blond temp colour on my largely white, but mixed with some dark and some grey - I like it.