No hue. A five-step grayscale ramp does everything color used to. Depth comes from contrast, weight, and rhythm, not chroma.
--paper
Page background
--surface
Card fill
--surface-alt
Alt surface / hover
--muted
Muted text
--ink
Text & borders, near black
--accent
Accent, inverted ink block
--paper
Page background
--surface
Card fill
--surface-alt
Alt surface / hover
--muted
Muted text
--ink
Text + borders
--accent
Accent, inverted ink block