Permanent hair dye after recently using semi-permanent?

[TheCowThatLaughs]

Is it ok to do this? I used the semi-perm dye on Tuesday and I can still see grey hair!! Would it be ok to go over it with a permanent dye? Thanks

It should be fine, I have done it with no ill effects. Leave the conditioner on for 20 minutes and you'll have lovely soft hair, with no greys hopefully!

Thanks Milk! I'll give it a go then