Function paint_entry_emphasised 

pub fn paint_entry_emphasised(
    scene: &mut Scene,
    transform: Affine,
    text: &mut TextRenderer,
    theme: &Theme,
    rect: Rect,
    colour: AlphaColor<Srgb>,
    label: &str,
    emphasised: bool,
)

paint_entry for a legend people point at: an emphasised entry (the hovered or chosen series) reads in primary ink.