I need to make lots of light grey fondant snowflakes and then colour them with silver petal dust.  The problem is that the colour grey changes to a light purple only a couple of days later.  Does anyone has had this problem before?  Is there a way to fix that?  I would really appreciate any suggestions.

AI have learned this tip from a cc memer before, to get gray mix light blue and a little bit of black until you achieve the desired look.

Thank you very much for the tip.  I'll try that.  Tomorrow is when I have to start making the snowflakes.

the silver will likely cover any purplish-ness (and/or the grey) anyhow 

I buy pre-made black fondant and mix it with white and it makes a nice gray that doesn't fade. 

I do have some black fondant I bought already pre-made. I think I will try that.  Thanks a lot for the tip.  I yes K8Memphis, hopefully the silver will cover it.  I tried the silver perl dust mixed with a tiny bit of vodka and it didn't seem to cover the whole surface as well as I thought.  It almost like I needed two coats. Anyway, I will be making the snowflakes tomorrow and I will be covering them with the silver in about two days.

Thanks again girls for the tips.

You can also use the Wilton silver spray it works very well to make things silver.

A silver spray?  I looked for something like that, but didn't find anything.  I live in Canada, in the Toronto area and we sometimes do not get the fabulous things you guys get in the US.  I will check again, just in case.