Single Process To Lighten Dark Brown Hair?

I am Mediterranean with typical dark brown, almost black hair with heavy red undertones and some greying. I am trying to find a hair color that will lift my hair to a medium or light reddish brown, but without having to lighten it with bleach first, which I have had to do because regular light brown hair color never lifts my hair enough and my hair basically just ends up looking like a drab brown. I don't have a huge issue with bleaching my hair first before depositing color, but what does bother me is treating my roots, as I find it almost impossible to bleach just my roots out without it getting all over my already treated hair. So this is why I would like to find a haircolor that will make my dark hair a nice reddish brown, without bleach, and that I can just apply to my roots without worrying if it gets on my already treated hair. Does such a product exist? Is there really a haircolor out their that will truly take dark brown hair to a lighter color in one easy step? Thanks for your help!

Thanks Susan! Let's hope the Pro's can figure this one out too..lol. I've seen on websites that there are haircolors made specifically to lift brown hair about 3-4 shades without brassiness, like this: