A scatter plot of the Iris dataset displays petal length against sepal width, with points colored by species. The visualization uses React state to track a hovered species in the color legend, dimming all other marks via opacity changes. The `ColorLegend` component captures mouse events, while `Marks` renders SVG circles. Axes use `scaleLinear` and SVG `<line>` and `<text>` elements from d3.v5, with data loaded by the `useData` hook using `d3.csv`.