The baby is a tort of some sort, not fawn. Fawn would have white inside the ears, around the eyes and the whole undercarriage would be white.
This also means the dam is a tort of some sort, not a sooty fawn.
If you bred an agouti of any variety to a fawn (which is an agouti based color) the probability of getting five non-agouti (solid colored) babies from that crossing is very unlikely. As in very, very, very unlikely. What you have is a litter of all solid colors, none of them have the white inside the ears of an agouti based color pattern. Which is still unlikely but within fairly easy possibility if it's an agouti to a tort.
black aa B_ C_ D_ E_
chocolate aa bb C_ D_ E_
chocolate tort aa bb C_ D_ ee
sable & sable? aa bb C chl D_ E_ (if they look almost black as adults, then they may be dark sable which is: aa B_ C chl D_ E_ . )
FWIW, all those colors are considered non-agouti or 'solid' colors. Is the male actually a chestnut agouti?
From your two parents, their genetic color chart based on their colors would be:
Agouti sire: A_ B_ C_ D_ E_ VM
Tort Dam: aa B_ C_ D_ ee
adding in the genes they have to have in order to have the offspring they did:
Agouti Sire: Aa Bb C chl D_ Ee VM. So he carries chocolate and non-extension (tort, fawn) dunno about albino or dilute.
Tort Dam: aa Bb C chl D_ ee Now you know she carries chocolate, dunno about albino or dilute.
Here's what the various letters mean:
Dominant A is Agouti, recessive a (two of them) for solid color patterns
Dominant B is Black, two recessives will produce brown (chocolate)
Dominant C and the bunny shows color, two recessives and it's an albino. There's also some more "C"s - dark chinchilla, light chinchilla, himi, albino
Dominant D and the color is Dense, two recessives and it's dilute. (Black to blue, chocolate to lilac)
Dominate E and the color Extends all the way down the hair shaft. Two recessives and only the yellow colors extend down the hair shaft. Can be modified by rufus/red
Vienna is dominant but is weird. Needs two to be a Blue Eyed White Rabbit. One dominant and it's a Vienna Marked, although can carry one and not show it. All your offspring from the buck should have "Possible Vienna Carrier" written somewhere on their pedigree.
Double check all this, it's late at night and I'm not checking my notes but just blithely typing.
