This work investigated the ability of fungus Trametes versicolor CCBAS AG613 to decolorize synthetic dyes congo red and malachite green under solid-state substrate cultivation conditions - on agar plates and dye-loaded lignocellulosic substrate. Fungus was cultivated on agar plates with the addition of dyes at final concentrations from 50 to 300 mg L-1, during 16 (congo red) and 38 (malachite green) days of cultivation at 27 °C. The diameter growth and the change of discoloration zone were recorded (in two perpendicular directions) every two days. White rotting fungus T. versicolor CCBAS AG613 showed the ability to decolorize dyes during cultivation on dyed agar plates, but the complete discoloration was achieved only in the case when malachite green was added at the concentration of 50 mg L-1. Dyed brewers’ spent grain (250 g brewers’ spent grain in 350 ml of dye solution, concentration of 150 mg L-1) was used as a substrate for solid-state fermentation. Cultivation was done in the horizontal-cylindrical laboratory glass reactor at room temperature. The temperature and the change of substrate mass were recorded continuously, while the relative humidity and the sample colour were ascertained after 7, 14 and 21 days of fermentation. Fungus T. versicolor CCBAS AG613 has shown noticeable growth on brewers’ spent grain substrate dyed with congo red and malachite green, which was evident in the temperature increase of the substrate layer and the substrate mass loss of 32.2% for congo red dye, and 37.49% for malachite green dye. Total discoloration (bleaching) was not detected. However, colour detection showed continuous increase in the change of colour and colour intensity of fermented samples compared to the abiotic control samples.