a little about ghost and snow for Sam
Ghosts and snows are actually made up of a couple of color mutations (in this case, deficiencies of certain colors).
A white snake who is a snow carries two traits that make it appear as such: amelanism and anerythrism (type A)
A muted grey-tone snake who is a ghost carries two traits as well: hypomelanism and anerythrism (type A)
If I break these down, it makes more sense to me. The three genes involved in making ghosts and snows then are amelanism, hypomelanism, and anerythrism.
Amelanism is a condition where the snake fails to produce the black/brown pigments (melanin). The name comes from a- lack of; melano- black color; -ism a condition of. Run it together -->a condition where there is a lack of black coloration, hence the amels you see around being the red and white snakes with varying degrees of yellow/orange thrown in. These guys always have red eyes since there is no melanin (pigment) in the irises to color the iris, and no melanin in the retina to make the pupil appear black. With the 'black' removed, you are left with whatever red and yellow the snake should have normally.
Anerythrism is a condition where the snake fails to produce the red/orange pigments (erythrin). {note: yellow seems to be affected independently and is not eliminated by anerythrism type A} The name comes from a- lack of; erythro- red color; -ism a condition of. Again, together you get anerythrism = a condition where there is a lack of red coloration. This results in a 'black and white' version of a normal snake. These are the grey-toned snakes we see around. There are other relatives to anerythrism type A that I am not going to get into here (charcoal/anerythrism type B, caramel, lavender).
It you think about it, what do you get if you combine anerythrism and amelanism...a snake that lacks the reds and the blacks leaving you with a white snake with or without varying amounts of yellow. There are other colors that will show up, pink tones, etc., that are governed indepently of the amel and anery genes. This gives us a wonderful variety within snows alone! Cool, in my opinion.
OK, onward...
Hypomelanism is a condition where black pigment is reduced but not completely obliterated. The name comes from hypo- a reduction of; melano- black color; -ism a condition of. Therefore, hypomelanism is a condition where black pigment is reduced. To confound the issue further, some believe that hypo may actually intensify the red tones making the snake more vibrant. Is this an effect of the gene or is the color just more visible without the black? I don't know, but I'd love to have someone prove it out!
Add hypomelanism to anerythrism and you get a black and white snake with muted blacks resulting in a washed out/silvery snake --> ghost.
Below is a picture (I hope) of a ghost and a snow for comparison.
I hope this helps!
The corn snake manual really does help clear it all up, you'll love it.