This stacked bar chart colors each bar segment by animal group—Domestic, Pest, Africa, Marine—using a custom scale with four shades per group, one per series (A–D). Built with D3 v5, it loads CSV data via `d3.csv`, stacks values using `d3.stack`, and renders SVG. The code assigns a unique color per segment, combining group and series indices, to differentiate categories beyond standard stacked-bar coloring.