Quick hair dye top up for weekend

[Indecisivelurcher]

I'm going to a wedding on Saturday. My hair dye (brown) is quite faded and some greys (not many) under the temples and parting. It's not ready to recolour. Is there a spray, gloss or shampoo that would give me a top up?

The L’Oréal root spray is pretty good, but go a shade lighter, and wrap a towel round your clothes before spraying as it can go everywhere.