I'm going to be a bit pedantic here Pasta.
Yes emulsions can be mixed perfectly well.
But..... adding a small sample pot is possibly not going to do much for the colour. It'll probably just make it a bit "muddy".
What you really need is a colour pigment/tint.
https://www.ebay.co.uk/itm/292477450062
Also........... with any colourants, you must mix the whole amount you need in one go. Otherwise, you'll never be able to "touch-up" any later damage.
Other than that: it's worth a shot :o)