Between Salon Touch Ups..what to use?

Hi All,

I have nearly 80% gray and have colored my hair for years.... first one color and then a couple of years ago I started wearing highlights, which I loved.

Now, due to some damage problems from several factors I am likely going back to one color (which for me is a level 6ish Lt Brown/Auburn)...

Anyway... my question is this... Obviously my hairdresser prefers I not put ANYTHING on my hair between salon visits... but since I need a touch up every 3 weeks, it is really hard to do! I like to see her no more often than once every 4 weeks, and I am very picky and sensitive about my white growth showing in between visits!

Can anyone tell me the safest/best way to get some temporary coverage between visits? I know about rinses and crayons but would prefer something that lasts a week or so.

What about 'Loving Care', or the water based colors in Beauty Supply stores? Which is a better/safer way to go between professional touch-ups?

I'd appreciate any help or feedback!

THanks,
Corihere