Sagewort looks like a chinchilla based color, I believe the Flemish Giant breed calls it 'light grey' (I looked up the Flemish colors at
Happy Tails Flemish Giants - Recommended Color Breeding.) There are five options on this, the 'C' color gene, in descending order of dominance. Melanin is the pigment base of all the rabbit colors;
eumelanin forms the dark colors like black, chocolate, lilac and blue;
pheomelanin forms the yellowish fawn/orange/red/cream shades. Most dominant is full-color
C, where both dark and yellow tones are produced as needed by the other genes. The fawn & sandy colors fall into this category, as the recessive 'e' extension gene extends the yellow to the end of the hairshaft, and yellow tones are fully produced by the full color 'C' gene.
Chinchilla is next down in dominance, where the dark colors are produced in full force, but the yellow tones are mostly eliminated, so a castor/chestnut agouti becomes a chinchilla. Your stock must have light grey recessives. A full color fawn only needs one full-color 'C' to show the yellow tones, as it is dominant, so you must have chinchilla
chd as the other gene for your stock.
Not involved in your colors would be sable
chl where yellow is eliminated as well as some of the dark; and pointed white/Californian/Himalayan
ch where all color is eliminated except on the cooler points. The most recessive of the five, albino red (or ruby)-eyed-white
c is where the pigment factories are shut down and no color is formed
.
Ermine is what happens when fawn/sandy yellows meets chinchilla that removes all yellow, leaving the pearl white coat. So, ermine is just a fawn non-extension chinchilla
(all rabbits carry two copies of each gene, one inherited from each parent; a dash is used when the second copy is unknown, because the dominant gene only needs one copy to express itself):
- A- for agouti patterning
- Your light gray appears to be a black-based color, with black tips, so B- for black
- c(chd)- for chinchilla in the light grey, Cc(chd) for the fawn that throws light grey would be my guess, although a recessive albino combined with a recessive light grey chinchilla from the other parent would also throw light grey.
- Fawn is the dilute shade of sandy, with less total pigment spread over the hairshaft, making the color lighter. In the same way, blue is the dilute of black, and lilac the dilute of chocolate. Blue chinchilla is the dilute of light grey. Your fawn carried the recessive dd, so their offspring will all carry at least one recessive copy of d.
- Fawn & sandy are both recessive extension ee, so all of their offspring will also carry at least one copy of recessive e.
So, there's my guess.