The invention relates to a concrete block producing device and to a method for producing colored concrete blocks using a concrete block producing device including a block molding machine with a block mold that can be supplied with fresh concrete from a concrete hopper. The concrete hopper can be supplied with portions of at least two differently colored fresh concretes in a controlled manner by a dosing device. The dosing device includes at least two dosing chambers and a transport device for transporting the differently colored fresh concrete portions to the concrete hopper. The transport device includes at least one positioning unit for guiding the colored fresh concrete from the dosing chambers to the concrete hopper. The positioning unit is designed to supply defined positions in the concrete hopper with differently colored fresh concrete portions.