pub const DEFAULT_SELECTION_BG: Color;Expand description
Single built-in fallback for the selection highlight when no
selection-color token is set - the platform “highlight” blue at ~40 %
alpha (mirrors macOS / web selection tints and Qt’s Highlight role).
Translucent on purpose so the text underneath keeps its contrast, so no
selection-text-color is required for legibility. Skins override the
whole look via the --lumen-selection token; this is the one Rust
fallback.