At least one cooling zone and a subsequent homogenization zone are installed between the inlet and the outlet of a forehearth for conditioning and homogenizing a stream of colored glass. The glass temperature in the forehearth is reduced from the inlet temperature T1 to an outlet temperature T2. In order to increase the cooling effect while simultaneously homogenizing the glass temperature at a throughput of at least 70 tons per day, a raised area is installed in the bottom along the length of the cooling zones to set a maximum bath depth Dmax of 120 mm. Furthermore, the cooling capacity is such that the temperature 20 mm above the bottom is reduced by at least 40.degree. C. in the cooling zone. In the apparatus used, the raised area above the bottom covers the complete length of the cooling zones K. The maximum depth Dmax of the glass bath is 120 mm above the raised area and in the homogenization zone the channel is at least 30 mm deeper.