Solid read - the part I found most surprising is the color can’t have a function, and the pink of Pepto-Bismol has an effect. Wonder how they resolved that from placebo.
I think that this comes from the opposite notion, not that the color has a function but where some purely functional property involves a specific color.
A knife manufacturer cannot trademark the color of stainless steel and prohibit other manufacturers to make steel knifes that look like they're made from steel, a chocolate manufacturer cannot use trademarks to restrict others from making chocolate that is chocolate-brown, and in a similar manner, bismuth subsalicylate simply is pink so Pepto-Bismol can't require other drug manufacturers to artificially recolor their bismuth subsalicylate tablets or use trademarks to prohibit them from selling bismuth subsalicylate as such.
