A while ago, if you wanted to get vitamin C from Boots (a British pharmacy chain), you would be presented with choices like these:
It is hard to see (and not just because the image is low resolution) that in one of these containers you would find orange-flavored tablets, while those in the other would be blackcurrant-flavored. Many customers failed to notice these flavor labels and brought home a product that was not what their loved one wanted. This design failed to prevent customers from making a mistake.
So how could Boots fix it? They could use the label color to indicate flavor, but they already used label color to differentiate different types of supplements:
Instead, they added a color background just to the flavor label:
This design makes the flavor options salient and is presumably much more successful at preventing customers from making erroneous choices. This design also has the potential of making flavor labelling consistent across their product line. Amazingly, however, as of March 2017, Boots has still failed to propagate this design upgrade to their other products (see for yourself):