Sumi palette
Merino Hollow
From #8e3636 ink through #a54b49, #007a82, #c36662 to #0097a2 light, Merino Hollow is a tetradic progression that holds together at any size. Use it for book covers that read at thumbnail size.
redsumifive-stop
#8e3636
#a54b49
#007a82
#c36662
#0097a2
The generator opens with #8e3636 as the primary and the next two stops as secondary and accent — adjust, check contrast, and export tokens or CSS from there.