Forgot that I was going to respond to this earlier today. The proper way to distinguish red from white vermouths is Italian and French. The Italian vermouths can be more or less spicy, herbal, sweet, etc., and like champagne, there are more dry and less dry French vermouths. I think of blanc vermouth like a blanc de blanc champagne, which is typically lighter and somewhat less dry than a typical brut/extra brut. Anyway, Dolin blanc is sweeter than Dolin dry, and that will be the same with other French vermouth brands that have more than one style.