The present invention relates to organic colouring agents with a high colour stability to weathering for thermoplastics. The invention furthermore relates to a polymer composition containing at least one thermoplastic and at least one organic colouring agent, preferably a combination of at least two organic colouring agents, of a specific structure. The invention moreover relates to the use of the colouring agents according to the invention for colouring polymer compositions, in particular for transparent formulations such as are required for the production of panes for use in buildings, motor vehicles and track vehicles or aircraft.