Not enough colorant in box?

I was just wondering if anyone else had the problem of not having enough colorant to dye your hair (all over color) in the box?

Usually, I use my Roots Only device to dye my roots every 2 months, but every 6 months or so, I like to do the all over color method because some fading can occur over time, and it seems as if there is never enough product in there.

I know -- buy two boxes. I just didn't know if this was a common problem or not? I also dye my daughter's friend's hair, and she has short (at the shoulder) hair, and there is always an inch of hair that seems to not get the appropriate amount of saturation. This is a question more out of curiousity (Garnier's 100% XL claims to provide more color for extra long or thick hair).

Kris :)

Sorry - my post was probably worded wrong.

What I meant was when you mix the colorant together (and the bottle is always full afterward), there is not enough left to cover your hair fully. I just thought maybe I might be applying too much to the roots for full hair application method, not saving enough for the mid-section and ends (when I do it this way - normally I just use the touch-up application method).

There is always a full bottle before coloring, but it's just the fact that I'm finding that I don't have enough to color my hair with (?).

Kris