Clairol Professional Shimmer Lights Blonde & Silver Shampoo
I stole a bottle of this Clairol Professional Shimmer Lights Blonde & Silver Shampoo ($9) from a dude I was dating who was going grey — he swore it helped bring out brighter tones. I've found it also works to dim the appearance of super-dark roots. (Though that's a look, too.)
Clairol Professional Shimmer Lights Blonde & Silver Shampoo