So, anyway, ramshorn snails (Planorbarius corneus) come in different colors, but the way they actually differ is sometimes hard to tell from photographs. So here is my descriptions of the main color morphs.
What it says, the snail has a brown foot and brown shell. When young, these snails have darker brown spots or dapples, but these usually fade away as the snail grows.
From a distance these look very similar to leopards. The snail has a brown foot. Under strong light the shell shows a blue-grey color with dark blue-black spots.
The snail lacks darker pigments. The foot is red and the shell is semi-transparent brown or bronze.
Broadly similar to the red snail, the "pink" has a red foot but a completely clear shell. Pink ramshorns were described in a wild population in a report by William Nelson in the May 1879 issue of the Journal of Conchology. They were described as "...of a bright flesh or pink color, the animals being mostly protruding from the shell and very conspicuous" (p. 150). But by the following year the brightly color variant could no longer be found. It seems likely that the color morphs now available are selectively bred from this kind of naturally occuring mutation.
I am told that white ramshorns also occur, however ramshorns without normal red blood are unlikely to thrive. It is more likely that they are yellow ramshorns, which have a yellow foot and clear shell.
Sometimes you will get a ramshorn with a red shell but a brown foot. These are not a "true" red and the shell will tend to become brown as it grows. Even true reds will tend to become browner as the grow, but any snail with a red foot is a red ram.
* Nelson, W. (1879). A variation in the color of the animals of Plamorbis corneus. The Journal of Conchology 2, 150.