highlighted hair 3 months ago, can I dye it now?

[3sisters]

I had highlights done 3 months ago through Groupon site for great price.
Now roots showing, no Groupon on sight and can't afford hairdresser, shall I dye on top. Oh and would love to keep the golden blond color! Roots=light brown.
Do you think i could go for golden blond and just leave it longer on roots?