I'm chiming in kind of late, but I wanted to add something for those of you who, like me, were blond in their teens and twenties and who now, through staying out of the sun or pregnancy or heredity, have gotten that "dishwater" hair. I've always been a little vain about my hair and had tried salon highlights. But the cost of them is so outrageous, and I hated the chemical factor so much, that I researched and tried some home highlighting.
Last weekend, I threw two chamomile tea bags in a 15 oz mug and brewed them for a few hours. Then I added about 1/4 cup lemon juice and had my husband work the whole mess through my hair. I gardened with a neighbor outside for a couple of hours, then washed my hair at night.
While this didn't add new highlights, it definitely accentuated the blonde already in my hair. My husband and neighbor verified that my hair looked blonder in the sun, especially around my face (where I really wanted it). Cost: free, since I already had the stuff.
Don't add too much lemon juice and make sure to wash it off your skin as it will burn you otherwise in the sunlight.
I plan to try honey in the wintertime--working it through my hair, wrapping it in plastic wrap, and letting it sit for several hours. Apparently this produces a very weak peroxide reaction that will lighten your hair a bit. I'll let you know how it works!