I was blonde many years ago -self dyed and wanted to return to a more natural colour (I was a light mousy brown) I went to a professional and they initially put a red dye one my hair to stop it going green, they then used a light ash blonde dye on my hair. It came out a conker brown with reddish lights. Over a period it faded to more or less my natural colour, which the stylist described as light ash blonde. I am not sure wether the colour you use has any bleach in it but if it has I would take some professional advice.