A style is a named, reusable set of rendering parameters applied when generating chart tiles. Styles are referenced by ID through the Core API when fetching vector or raster tiles, allowing client applications to use a custom color palette or display settings without rebuilding the underlying chart data.

Themes

Each style is created from a base theme that determines the default color palette. Three themes are available:

• day: Light palette intended for use in daylight conditions.
• dusk: Mid-tone palette intended for use at dusk or in low-light conditions.
• night: Dark palette intended for use at night.

The theme is set on creation. The resulting style’s color palette and display settings can then be customized by updating the style’s parameters object.

Parameters

The parameters field is an object describing how the style renders. It contains two keys:

• colors: An object mapping color slot names to hex strings. Slot names are determined by the rendering engine.
• settings: An object containing display toggles, including:
  • iconSet: The name of the symbol set to use for chart features.
  • soundingOpacity: Opacity of depth soundings, between 0 and 1.
  • showLightSectors: Whether to draw light sector arcs around lighthouses.

Other display settings may be added over time. Unknown keys in the parameters object are preserved.