Dear Ms.Yap,
Now Amanda is not in Thailand, She will come back on Aug 18, 2014. When she come back, she will make an appointment with Mr.Lin to talk more detail about it.
Anyway,if you have any problem with the color shade that we provide you from the begining we can offer you other the product which is the same kind, I think it's work with this product and use low concentration than Tr-173AH so save more money. We can do the test and we will send you the sample to you. If you happy with color shade, we can talk more detail about it.