UNSTANDARDISED BREEDS
There are quite a few different breeds of cavies which are not exhibited in Australia - yet are standardised overseas.  Below are a number of these breeds, with a brief description.
(All photographs and information courtesy of Crystal Cavy Stud, UK)
THE FOX
This is a one of newer breeds overseas.  It has either a black, chocolate, lilac, slate or beige body colour.  The belly, eye circles, top of ears, nose, inside of legs and inside of ears are white in colour.
THE MARTIN SABLE
This breed is very similar to the Fox, with the expection that rather than being a self colour (such as black or chocolate), it is a Sable colour. To view the
THE TAN
I dont have any information on this breed, but far as I know, it is similar to an agouti, but without the ticking - meaning that it has one solid colour on top, with another solid colour on the stomach
     including bonnet strings.                                                          
THE HIMALAYAN (aoc)
THE PINK EYED CREAM
The cream standard states for dark / ruby eyes.  This breed, sometimes called the ivory, has pink eyes.
THE SOLID AGOUTI
This breed is very similar to the
agouti, with the exception that it has the agouti ticking covering the entire body, including the stomach.
THE SOMALI
This unusual looking breed is actually an abysinnian with a rex coat - a cross between the
two breeds.
THE SKINNY PIG / BALDWIN
Known by these two names, this is a guinea pig, without fur! However, some have a small patch on their faces.  The skin can be any colour - any markings.  Their skin is said to have a warm feel, but these cavies can suffer from dried skin - so that needs to be watched.
BACK TO MALIBU PIGSHED                                        BACK TO CAVY BREEDS AND STANDARD
THE RIDGEBACK
Like the dog, this breed has a ridge alongs its back and comes in any colour pattern.  The ridge is meant to start between the ears - and be all the way down the spine.
ABOVE
A pair of young black foxs
ABOVE
An adult martin
LEFT               
This is an example of a lilac/tan - with lilac on top, and the tan on the stomach
As the name suggests, this breed is the same as the chocolate or black himalayans, but have a different self colour points.
ABOVE
A beige himalayan (left) as well as a self beige.
**NEW AND    IMPROVED
    FORMAT**
         ABOVE
A pink eyed cream (which also happens to be crested)
THE LILAC SABLE
This breed has the same marking pattern as the regular
sable, but is lilac in colour rather than chocolate / beige.
ABOVE
A lilac sable cavy
ABOVE
A solid agouti cavy
        ABOVE                                      ABOVE
Side view of a ridgeback         Top view of a ridgeback

(photos courtesy of Nicole Johnson, Bivoir Cavy Stud, NSW Australia)
RIGHT
A red somali cavy
ABOVE
A "baldwin" cavy
ABOVE
A "baldwin" cavy
Sable standard
click here.
RIGHT
a line-up of the 5 colour variations recognised in the USA

beige, lilac, slate, chocolate and black
(photo courtest of Tracy Iverson, Iverson's Stud, USA)
LEFT
2 Chocolate Tans

(photo courtesy of Tracy Iverson)