There is an irony here that only becomes apparent later in the chapter, when we
reach Mrs Gould's watercolor of the unspoiled San Tomé gorge. Green is
"the color of hope" because it represents growth and nature, but the
mine has devastated actual nature and replaced it with green paint on dead wood.
"Green" has thus been transformed from a living force into an abstract
and inanimate ideal, precisely by betraying the life of the thing it purports
to represent. In that sense it is a microcosm of the same process at work in the
vast, barren optimism of material progress, and indeed in the life cycle of all
dream-ideals. Thus the paint, which functions as a clumsy symbol for the workers,
holds a much deeper symbolism for the reader.