Bivariate Hue Blending – A Tool for Designing Bivariate Choropleth Color Schemes

This paper discusses the relevance of bivariate choropleth maps particularly of the sequential/sequential or diagonal focal model type, designed to be used for visualizing two correlated quantitative variables. It then describes an interactive prototype tool for designing color palettes to be used on this type of bivariate choropleth maps, based on rotating hue angles in the Hue Chroma Lightness color space.