The Disease Zones Expand emergency event card states to
Add 1 cube of every non-matching color to each city with different colored cube(s).
Does this mean to add cubes to cities which have cubes of non-native colors (e.g. LA has a blue cube but no yellow cube, so it gets a second blue cube, and Mexico City has a blue and a yellow, so it only gets a second blue), or add cubes to cities which have cubes of 2 or more colors (e.g. LA has a blue cube but no yellow, so it gets no new cubes, whereas Mexico City has both a blue and a yellow, so it gets one extra of each)? Or is it something in between?