Of course, I could be not remembering correctly, but I think it was Pam who always used ..... taco shaped () if a female, and donut shaped O if a male. As they get older, you will see the penis pop out when you press on thegenital area. If you press too hard, you can very easily change an O to an (), tho.
The basic color should stay pretty much the same ... maybe a little difference in the shading.
As far as the nest box ..... When only a single or up to four ... depeding on how big the babies are and how they are doing ... I usually left the nest box in till they were absolutely not using it anymore. Sometimes this is the only relief that Mom gets from the babies latching on to her ALL THE TIME. She can hop up on the top of it (mine are covered half way on the top) and till the babies can hop up there, Mom can enjoy a few minutes of peace.
When decent straw (absorbs better than hay) became so darn hard to find, I stated using the pine chips for the nest boxes. Even kindling in the dead of winter, the babies stayed nice and warm. And I rarely changed any of the bedding.
At first, being new to the rabbit world, I was SO careful when fostering ... using just about anything to make the babies smell the same ... or sometimes just putting whatever it was on the Mom's nose so EVERYTHING smelled the same to her. Then I found out by trial and error that you do not have to do that. And I always handled kits from the get-go just by doing the daily or so head count to see if there were any deads in the nest. I used to go thru 1000 pounds (one thousand) of rabbit food in a week, so I handled a lot of bunnies. I never had a doe refuse a kit just because I had handled it.
I always found that kits open their eyes about the same as kittens ... right about 10 to 12 days. Had very few develop nest box eyes. An old time breeder/show person told me that if I did, just to draw a little regular penicillin up in a syringe, take the needle off, and then hold the eye open and drop the penicillin right into the eye. This did work for me.
I love the Mini Rex ... just have a few Dwarf Hotot and Mini Lop now. Someday ........ I hope to get a couple of the Mini Rex again. They have the darnedest sharp claws, but to feel their hair is like feeling a bit of Heaven. And every one that I had was ever so friendly. One of my house rabbits was a Mini Rex buck ... Mickey ... and he didn't come to the house till he was close to 8 months old and got so terribly sick. And he used my homemade litter box to at least pee in. At one time, I crossed the Mini Rex with the Mini Lop. Ended up with two second generation Velveteens ... male and female ... both solid black. One died before I had the chance to breed the two of them to see what I would get.
The kits grow so darn fast. Enjoy this little one while you can!
~ Dolores