Can I use Loreal True Brunettes Ultra Light Natural Brown on reddy dark brown hair?

I have been dying my hair dark brown (with red tones) for years, and want to lighten it a couple of shades. I haven't dyed it for at least 2 months, would it be ok to use Loreal Ultra Light Natural Brown (UL51) on it or would it turn orange? My natural hair colour is mousey brown - I have a few inches of roots.Can I use Loreal True Brunettes Ultra Light Natural Brown on reddy dark brown hair?
You could. But it would most likely turn out to be the same or orange. For more trustworthy results you should get your hair bleached before dyeing.