Clairol changed formula & my hair color

Hello,
    Due to a thyroid condition, my hairdresser friend told me no peroxide and no ammonia. I now use Clairol Loving Care Auburn #80. The dark brown hair stays dark and all the gray turns red. So I now have a LOT of red. LOL Problem I bought several 4/30 hair pieces which looked great, until they changed the formula. Oh Yes They Did. They swear the formula is the same but my hair is now 4/130. Looks great love it bought all new hair pieces. Oh, but wait, it gets better. Auburn #80 is for some reason hard to find. So when I got the chance I purchased six boxes. Turns out some of them are OLD formula and some of them are NEW formula. I called the 1-800 number just to ask how to tell the difference between the old and new. They denied any change and blamed it on my technique. So I took two clippings from my hair, at the same time from the same location on my head. Colored one swatch in the near empty bottle of the old formula and one swatch in a new formula. You guessed it, one is 4/30 and the other is 4/130. So does anyone know how to tell the manufacture date on Clairol Loving Care Natural Instincts? Thanks so much. Victoria

yes, clairol changed to soy based from oil based.