Sumi palette
Copper Inn
From #8c1401 ink through #b94936, #d86550, #df7c69 to #fe9885 light, Copper Inn is a analogous progression that holds together at any size. Use it for book covers that read at thumbnail size. The darkest and lightest stops clear AA as a text pair.
redsumifive-stophigh-contrast
#8c1401
#b94936
#d86550
#df7c69
#fe9885
The generator opens with #8c1401 as the primary and the next two stops as secondary and accent — adjust, check contrast, and export tokens or CSS from there.