The invention relates to a forehearth coloring device for preparation of colored glass. The forehearth coloring device comprises a forehearth, wherein the upstream of the forehearth is communicated with the uptake of a kiln for molten glass production; a pigment concentrated solution kiln is mounted at the upstream part and on the side surface of the forehearth and communicated with the forehearth through an inflow channel, a valve is mounted on the inflow channel for on-off control, and a discharge outlet is formed in the bottom of the pigment concentrated solution kiln; a first stirring pool, a weir, a partition board and a second stirring pool are sequentially arranged in the forehearth and at the downstream part of the pigment concentrated solution kiln, the partition board is provided with a throat, a plurality of heating electrodes are arranged in the forehearth and in the downstream position of the pigment concentrated solution kiln, and a discharge port is formed in the tail end of the forehearth. With the adoption of the forehearth coloring device for preparation of the colored glass, online rapid change of a pigment concentrated solution can be realized, and mixing uniformity of the pigment concentrated solution and molten glass is improved.