OptionalcolorText colour.
OptionalfontFont faces, the first one available wins.
OptionalhaloColour of the halo drawn around the text, for legibility.
OptionalhaloWidth of the halo, in pixels.
OptionalopacityText opacity, 0 (transparent) to 1 (opaque).
OptionalsizeFont size, in pixels.
How a module's text labels look. Sizes and widths are in pixels, and every field also takes a MapLibre expression.