Blue Hour palette
Ember Bluff
Dark anchor, working middle, light release: #004658, #00708b, #308ba7, #5299b1, #6eb5ce form a split-complementary blue hour set with somewhere to stand at every lightness. Made for book covers that read at thumbnail size. The darkest and lightest stops clear AA as a text pair.
cyanbluehourfive-stophigh-contrast
#004658
#00708b
#308ba7
#5299b1
#6eb5ce
The generator opens with #004658 as the primary and the next two stops as secondary and accent — adjust, check contrast, and export tokens or CSS from there.