shadowTint property
The ink this brand's depth shadows are cast in, or null for the kit
default (a blue-grey on light backgrounds, pure black on dark ones).
Shadow geometry is shared across brands so surfaces agree on how far off the page they sit; only the hue is brand-specific. A warm palette under a cool grey shadow reads as a foreign cast — which is the whole reason Bloom sets this.
Presets also feed this into ColorScheme.shadow so Material's own elevation shadows (Card, Material, AppBar) pick up the same ink.
Implementation
final Color? shadowTint;