The palette
A brick city wants a warm ground, red-brown through to rust, and at this scale the ground is most of the sheet, so that choice decides the print. Keep your darkest value for the water, because the water is the only line here with an argument: the canals straight and deliberate, the rivers thin and half-hidden. Mark the outer motorway ring once, in a light grey, purely to give the conurbation its scale. Resist adding green; there is little of it, and inventing some would soften exactly what makes this drawing severe.