Hi there.
Unfortunately you can’t do this.
I’ve just had a looksie and the colour of the nail polish changes when you change your face makeup. Sometimes it changes to a lighter colour almost skin coloured, some turn to black. But, on some of the make ups, notably the older designs, the nail polish does change colour.
I changed my make up to the purple lips one and my toe nail polish changed to purple.
You would have thought that the Devs would have changed this to matching finger and toe nails matching, but alas, they haven’t and most probably won’t.