The M1 runs shallow under Andrássy út — so shallow that its rooms are wide and short, and every surface is within arm's reach. That proximity is why the line was built out of glazed ceramic: a dark chestnut Zsolnay dado you can lean on, a white tile field above it, and station names fired into the clay at Pécs rather than painted on.
This system takes the brown as the ground, not the white. Type is light on chestnut, the tile field appears as a band and never as a page, and line yellow reads as a flat signal colour. Ornament stays where it lives in the stations: column capitals, sign frames, corner motifs.