Thanks John for the answer.
Can we ignore this change of color in winter/summer or it's too noticeable and detectable ? (maybe it depends of each one.) What does people normally do ?
It's easier to send a hair sample just one time and then you keep it in my toplace folder; and not send another sample every change of season!!

I'm happy to hear that you can match the textures too. Now I think the both hair really matches ! I'm looking forward to see it.

My last question : Can we dye our hair with a toplace unit ? Or doesn't it work with the lace and it will dye the lace too ? If it works we are sure to have exactly the same colour and it's more undetectable.