Reference

All functions
adjust_contrast_pair()	Adjust Contrast Between Two Stroke Colors
geom_curve_dual()	Dual-Stroke Curved Line Annotations
geom_curve_dual_function()	Dual-Tone Curved Function Lines
geom_lm_dual()	Dual-Tone Regression Line with Contrast-Aware Strokes
geom_segment_dual()	Dual-Stroke Line Segments with Vertical Offset
geom_text_contrast()	Contrast-Aware Text Geom