Inorganic and organic dyes for coloring of polymeric materials are known. The inorganic dyes are thermostable, but for the coloring of plastics huge quantities of dyes are necessary and it is very difficult to obtain colored transparent materials. The organic dyes are not stable at high temperature and for the coloring of plastics a huge quantity of dye are consumed. Previously coordination compound of vanadyl(II) with ligand obtained by template condensation of acetylacetone Smethylizothiosemicarbazone with 1-hydroxy-2naphthaldehyde [1] was synthesized (fig). The complex has been studied as dyes for the polystyrene and polyethylene. It was shown that this complex is compatible with different types of polystyrene and polyethylene with high and low density. Materials with uniform and transparent claretred colour have been obtained. It should be noted, that the amount of dye used for coloring polystyrene (block, emulsion or suspension) and low or high density polyethylene is very small (0.005 to 0.01 g medium tone, 0.015 to 0.035 g intense tone to 100 g polystyrene and 0.006 - 0.010 g medium tone, 0.05-0.100 g intense tone to 100 g polyethylene). Varying the dye concentration, transparent plastic parts with different shades or nontransparent ones can be obtained. The obtained pieces are colored evenly, possess a high photostability and are stable towards physico-mechanical processing. Due to the accession of compound to polystyrene, its use as dye for thermoplastic masses does not need additional requirements to process granules and in this case the dye consumption is reduced significantly. Due to the coloring capacities, together with other useful properties, such as large thermostability and photostability, and very simple and inexpensive methods of synthesis, the proposed complex is deemed better than known analogues and can be used as colorific agents.