The Containment Specialist role card says the following:
When you enter a city with 2 or more cubes of the same color, remove 1 cube.
We played yesterday with the mutation purple disease, and had a city with two red and two purple cubes. When the Containment Specialist entered that city we weren't sure whether we could remove one cube in total, or one cube of each colour.
In the instance, we opted to allow the removal of one of each colour, but still ended up losing because we ran out of cubes.
How many cubes should we have removed?