Data visualizations often exclude users with visual impairments and temporary or situational constraints. Many regulations (European Accessibility Act, American Disabilities Act) now mandate inclusive digital content. Our research provides practical solutions — optimized color palettes, supplementary patterns, and alternative formats — implemented in popular libraries like Bokeh and Vega-Altair. These techniques, available through our open-source cusy Design System, create visualizations that reach broader audiences while meeting compliance requirements and improving comprehension for all users.