Ramshorn snails: experimenting with color genetics

After careful observation of snails obtained from my pond, I discovered naturally-occuring morphs of the common ramshorn snail.  Of course there was the most common red morph, but after a few generations other colors started cropping up:

 

So far there are at least 4 specific color genes at play: red body, yellow body, white/pearlescent shell, and yellow/clear shell.  In addition, leopard spots are a pattern that can appear on any color.  Some of the colors in the above chart are currently theoretical as I haven't personally seen them (purple-gold).

Examples of colors in vivo:

Wild/brown
Blue (with leopard)
Jade
Red
Pink
Red Gold
Chocolate
Ivory
Gold
Purple
Lavender

Theory: purple body snails are heterozygous for red body, thus red body is co-dominant.