Blue Hour palette
Terracotta Oasis
Dark anchor, working middle, light release: #004073, #1b68ab, #3a83c8, #5793ce, #73afec form a tetradic 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.
skybluehourfive-stophigh-contrast
#004073
#1b68ab
#3a83c8
#5793ce
#73afec
The generator opens with #004073 as the primary and the next two stops as secondary and accent — adjust, check contrast, and export tokens or CSS from there.