There is a breed called beige, developed in The Netherlands and later adopted in the UK, where it was also known as Isabella for a while. The picture I have looks like a lilac tort to me and the breed's build is described as "like Havana" (see
http://www.thebrc.org/standards.htm under N7) which I think also suggests a chocolate base. On the other hand, the BRC standard describes the nose shading as "blue" and if you select "shaded self" on
the BRC colour list it gives the genotype of Beige/Isabella as aaB-C-ddee, which is blue tort.
As a colour in other breeds, all the sites I found identified beige as a blue tort and gave isabella as another alternate name.
this mini-rex site gives isabella as an alternate name for blue tort in mini-rex, but notes that it is not showable.
But none of this would explain why your link has grouped it with chinchilla, at which point I found
this old thread with this gem:
pamnock":37jxsedc said:
"Beige" (choc. chin) isn't an accepted variety, but it was one of the original varieties presented for the Mini Rex. It was a presented variety in 2009 for Rex (failed).
EDIT: forgot to address fawn
As I understand it (or misunderstand it), red, orange, fawn, and cream are always A_C_ee. Red and orange are always high rufous and D_, cream is always dd, and fawn is either a low rufous D_ or a high rufous dd. As for which breeds or countries use which, I've never tried to make sense of it.
