Bleaching my hair more then once?

So almost two months ago i put my own highlights in my hair. My hair is very dark and shockingly, i got it to a very light yellow color after about an hour total of it being in my hair (same day, different hours). I was just curious, if i go back in and bleach those pieces more, will they turn any lighter? (trying to avoid toner). Im guessing its reached its peak of lightness considering how dark my hair is but it doesnt hurt to ask(: