How Can I Dye My Own Hair To Match The Hair Piece Colour?

[F.Coronilla]

hello, i really like the piece colour, is a mix betwen 7.34 and 8.34 that look pretty close to my own hair colour, but i want it look like 90-100% similar so i try to dye my hair but when i use the same mix to dye my hair, it dont match, what can i do? any suggestions?

thanks a lot