a text style of a theme: size in DIP (24.8), line height in DIP, weight 100..900; None =
the style’s (a size alone scales the style’s line height with it)
the WCAG 2 contrast ratio of two colours (alpha ignored): 1 (equal) .. 21 (black on
white); text needs 4.5 (large text 3), graphical objects and controls 3
the tokens of a high-contrast scheme: opaque fills from its colours, borders and strokes
in the text colour, accents in the highlight colour, links in the link colour