Jewel palette
Polar Reef
Five jewel stops with room to breathe — #123fa0 grounds, #3c6bca and #5687e9 do the talking, #6d98ec softens, #8fb6ff lifts. The analogous bones keep it coherent across book covers that read at thumbnail size. The darkest and lightest stops clear AA as a text pair.
skyjewelfive-stophigh-contrast
#123fa0
#3c6bca
#5687e9
#6d98ec
#8fb6ff
The generator opens with #123fa0 as the primary and the next two stops as secondary and accent — adjust, check contrast, and export tokens or CSS from there.