Susan has a basic hair color chart in the LongLocks Boutique under Hair Color Chart. 

If that does not give you enough options, I'd suggest checking out the examples used on hair coloring products.  Find one close to your color and see what they call it.

I"m in the same boat - other than the hair that has lightened with sun exposure, my hair is somewhere between blonde and light brown.  The ends are certainly blonde, but the roots would probably be closer to light brown with plenty of silver streaks.

My understanding is that the general types of hair color on the brown/blond continuum are golden brown/blond, red brown/blond (AKA auburn/strawberry), and ash brown/blond.

So if your hair has golden highlights, it fits in the golden brown/blond category. If it has neither golden nor red highlights, then it's ash.

You then add "dark" or "light" if necessary to describe it better.

Light golden brown, dark ash blond, etc.