Question about black torts

[Cedar Point Rabbitry]

I was wondering about the following two rabbits...they're both Black Torts, the doe Broken Black Tort and the buck Solid Black Tort.

Now, the buck is almost completely black on his nose. He's really dark. Both parents are torts.
And the doe is very, very light. Almost no shading. Out of a Broken Black Tort and a Harlequin.

Why is that? Is there a chance the doe's not really a black tort?

 

[Dood]

She is just a VERY light one with very little umbrous factors

 

[Cedar Point Rabbitry]

What's umbrous factors?

 

[Dood]

Darkening modifiers

Rufus modifiers enhance or reduce red, umbrous enhance or reduce black

 

[Cedar Point Rabbitry]

Ohhh, okay, thanks!