In one embodiment, an over-voltage protection circuit is configured to have two control circuits that respond at different values of the input voltage. Colors of the similar hue are rendered with a first colorant, a second colorant or a blend of the first and second colorants depending on which region of a color specification space the color specification is related. A vent is operatively connected to the air port to vent the pressurized container to draw froth from the printhead assembly through the liquid port into the container. The dose may be administered as a tablet, a liquid, or a powder.