A device for producing a dyed plastic melt and an undyed plastic melt includes a multi-shaft screw extruder, a first metering installation, a second metering installation, and a control installation, selecting between a first operating mode for producing the dyed plastic melt and a second operating mode for producing the undyed plastic melt. The first metering installation feeds an undyed plastic material through a first infeed opening into a housing of the multi-shaft screw extruder, and the second metering installation feeds at least one dyeing agent through a second infeed opening into the housing. In order for the undyed plastic melt to be produced, the plastic material is fed exclusively via the first infeed opening such that residual dyeing agent which is still located in the second metering installation or in the region of the second infeed opening does not contaminate the undyed plastic melt.