Wow......you are really lucky then.
I've tried that product for the same reason, but....my roots/ hair turned orange.
Went to my stylist for a color correction for the highlights, and asked her on what the heck happen.
She told me, that in order for my hair to actually turn blond, she needs to use bleach.
And, that the formulas at the store are weaker in concentration (for safety reasons) then me and my hair would need in order to lift my red pigments out.
OK...so....I ran around like a carrot for a day or two, but learned my lesson.
Lucky you !!!