Pigment-less translucency and fineness of pallial tentacles often make discernment difficult (1), especially when mantle skirt retracted from shell-rim and pallial tentacles viewed against shell; translucent tentacle then takes on colour of shell behind it (2).
Foot colour varies greatly on P. vulgata, sometimes, like this one, as dark as on some P. depressa.

OTHER SPECIES ALBUMS
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