Black smoke or fever coat

[Lehi]

I just adopted a shorthair 11/12 week kitten with an interesting coat. It has black fur with what appears to be a shorter gray undercoat. I have been googling like a fool trying to figure out if it will stick or not.
His brothers were both gray and sister is similar but more black.

 

[Flybynight]

Hi,
Super cute I lean towards fever coat but time will tell.

 

[sivyaleah]

As someone with a black cat, who was lighter than this when a kitten, I'm leaning to fever coat as well.

 

[Meowmee]

Maybe a fever coat. She is adorable It is amazing how gray she looks In the first photo and how black in the second. I am going to research it and post more later.

 

[Maurey]

Fever coat. The inhibitor gene causes high contrast white roots.

 

[hortusgirlii]

look under tail, and at roots for stark white , usually in a smoke you see some white showing through on face, but low grade smoke can be harder to see

 

[Meowmee]

Just to give more info... A smoke coat will have white/ light roots and a fever coat has dark roots like others have said. A fever coat is caused during development before birth perhaps by mom being ill, stressed or on medications, it usually causes no harm to the kittens, it just inhibits the development of pigmentation. Eventually in this case with the kitten being grey in appearance the fur will turn black if it is a fever coat. A smoke coat is determined by an inhibitor gene Ii and is dependent on other factors such as the base coat color and agouti/ non agouti as well as which inhibitor genes were inherited.

Here are some links.

• The inhibited pigment gene, I/i. The dominant allele (I) produces tipped hairs that are fully colored only at the tip and have a white base. This allele appears to interact with other genes to produce various degrees of tipping, ranging from deeply tipped silver tabby to lightly tipped shaded silver and chinchilla silver. The inhibitor gene interacts with the non-agouti genotype (I-aa) to produce the color known as smoke. The homozygous recessive genotype when combined with the agouti gene (iiA-), produces tabby coloration, which can vary along a spectrum ranging from a deeply patterned brown tabby, to a lighter "golden tabby", to the very lightly colored shaded or chinchilla golden colors. Orange cats with the inhibitor gene (I-O-) are commonly called "cameo".

Cat coat genetics - Wikipedia

Cat coat: silver and smoke cats — The Little Carnivore
Black Smoke Maine Coon Kitten vs Fever Coat

Fever Coat: What is it?
Amazing Color-Changing Kittens: What Is Fever Coat?