Blue Hour palette
Sleepy Delta
Dark anchor, working middle, light release: #005e96, #3188c9, #50a4e7, #6fb4ed, #99d0ff 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 for large text.
skybluehourfive-stop
#005e96
#3188c9
#50a4e7
#6fb4ed
#99d0ff
The generator opens with #005e96 as the primary and the next two stops as secondary and accent — adjust, check contrast, and export tokens or CSS from there.