A device for mixing a plurality of fluids to formulate a mixture and for dispensing the mixture, the device comprising: a plurality of cartridge assemblies each comprising a cartridge configured to contain one of the plurality of fluids; a plurality of flow channels each having a central axis and each configured to communicate with a corresponding one of the cartridges; a manifold assembly, comprising: a manifold body having a mixing chamber and a plurality of inlets each configured to communicate with a corresponding one of the flow channels through which the fluid from the cartridge of the corresponding cartridge assembly is drawn into the mixing chamber during operation of the device; a spring disposed within the manifold body; and a piston disposed within the manifold body; a dispensing pump assembly configured to communicate with the manifold assembly and configured to draw fluid from each of the cartridge assemblies; and a nozzle configured to communicate with the dispensing pump assembly and to dispense the mixture; wherein during operation the dispensing pump draws a volume of fluid from each cartridge through the corresponding flow channel and through the corresponding inlet into the mixing chamber to form the mixture, and wherein during operation the mixture is drawn from the mixing chamber through the dispensing pump to the nozzle, characterized in that the device further comprises a plurality of valve assemblies each positioned to communicate with one of the flow channels to adjust a mass flow rate of the fluid drawn from the corresponding cartridge; the manifold assembly further comprises a seal disposed within the manifold body adjacent to and having a size and a shape that substantially covers the inlets; and the piston is disposed between the seal and the spring, wherein the spring is moveable between an extended position in which the spring engages the piston to move the seal to a closed position that substantially and simultaneously closes the inlets from the flow channels and a compressed position that moves the seal away from the inlets to substantially and simultaneously open the inlets to the flow channels. a plurality of cartridge assemblies each comprising a cartridge configured to contain one of the plurality of fluids; a plurality of flow channels each having a central axis and each configured to communicate with a corresponding one of the cartridges; a manifold assembly, comprising: a manifold body having a mixing chamber and a plurality of inlets each configured to communicate with a corresponding one of the flow channels through which the fluid from the cartridge of the corresponding cartridge assembly is drawn into the mixing chamber during operation of the device; a spring disposed within the manifold body; and a piston disposed within the manifold body; a manifold body having a mixing chamber and a plurality of inlets each configured to communicate with a corresponding one of the flow channels through which the fluid from the cartridge of the corresponding cartridge assembly is drawn into the mixing chamber during operation of the device; a spring disposed within the manifold body; and a piston disposed within the manifold body; a dispensing pump assembly configured to communicate with the manifold assembly and configured to draw fluid from each of the cartridge assemblies; and a nozzle configured to communicate with the dispensing pump assembly and to dispense the mixture; wherein during operation the dispensing pump draws a volume of fluid from each cartridge through the corresponding flow channel and through the corresponding inlet into the mixing chamber to form the mixture, and wherein during operation the mixture is drawn from the mixing chamber through the dispensing pump to the nozzle, characterized in that the device further comprises a plurality of valve assemblies each positioned to communicate with one of the flow channels to adjust a mass flow rate of the fluid drawn from the corresponding cartridge; the manifold assembly further comprises a seal disposed within the manifold body adjacent to and having a size and a shape that substantially covers the inlets; and the piston is disposed between the seal and the spring, wherein the spring is moveable between an extended position in which the spring engages the piston to move the seal to a closed position that substantially and simultaneously closes the inlets from the flow channels and a compressed position that moves the seal away from the inlets to substantially and simultaneously open the inlets to the flow channels.