I have had 9 cats. All of my black cats (there have been 4-- Crystal, China, Kowo and Harley) have started out black and remained so, although all of them, with the exception of Harley have had little stray white hairs, either under their necks, or on their bellies. Harley is completely black. My orange tabby (Hobbes) was a fluffy little ball of orange fur with light stripes and white on her belly and was the same until she died at the age of 10. My tortouse shell tabby (Tigger) started out grey with black stripes and remained that way. I got Amber (an orange Tabby), Rabbit (a beautiful, completely white cat whose coat looked like a white rabbit, albeit with a nasty attitude) and Mollie ( a calico) when they were adults, so I have no idea what they looked like as kittens.
Currently we only have Harley and Mollie.