Black Face Fawn
Note that blackfaced fawn females can be difficult to distinguish from fawn females. Generally, though, they're a little bit darker in colour between beak and tear markings and on the belly.
Black Face Isabel
This combination can be very attractive if the Isabel mutation is in the dark form. In some countries, and here in the Zebra Finch Designer, the Grey Isabel is the dark form, while the Fawn Isabel is the light form.
Black Breasted Black Face Fawn
Black Breasted Black Face Fawn should have big orange cheeks, and they should be as black on the belly as possible.
The Fawn Isabel is the light form of Isabel. You should not see any of the usual black markings at all.
Black Breasted Orange Breasted Isabel Fawn
This is a very attractive combination where all black has been reduced while orange has been retained.
The Fawn mutation changes the black and grey pigments to fawn (brown) pigments.
The Black Breasted mutation changes the pattern of the markings.
The Black Face mutation causes the belly and the area between tear mark and beak to be filled with black pigment. Ideally, the belly should be as black as on the picture, but in real life, it is often less black.
The Orange Breasted mutation causes black areas to become orange.
The Isabel mutation causes black, grey and fawn pigments to be diluted, while the orange pigments remain intact. The degree of dilution can vary.