John Frieda blonde go blonder spray?

I am naturally dirty blonde but it's a really dull color so I have been dying my hair brown but I haven't dyed it for about 8 months so it's faded out and I have some lighter strands that are my natural color and the top half of my hair is lighter (long hair) I kind of want to go a little lighter for summer so will the spray work for me I my hair look light brown? Will it turn the lighter strands into highlights?