diff --git a/client/__tests__/e2e/cellxgeneActions.js b/client/__tests__/e2e/cellxgeneActions.js
index 50fbfe23..0f5bf77c 100644
--- a/client/__tests__/e2e/cellxgeneActions.js
+++ b/client/__tests__/e2e/cellxgeneActions.js
@@ -182,6 +182,24 @@ export async function createCategory(categoryName) {
 
 */
 
+export async function colorByGeneset(genesetName) {
+  await clickOn(`${genesetName}:colorby-entire-geneset`);
+}
+
+export async function colorByGene(gene) {
+  await clickOn(`colorby-${gene}`);
+}
+
+export async function assertColorLegendLabel(label) {
+  const handle = await waitByID("continuous_legend_color_by_label");
+
+  const result = await handle.evaluate((node) => {
+    return node.getAttribute("aria-label");
+  });
+
+  return expect(result).toBe(label);
+}
+
 export async function expandGeneset(genesetName) {
   const expand = await waitByID(`${genesetName}:geneset-expand`);
   const notExpanded = await expand.$(
diff --git a/client/__tests__/e2e/e2eAnnotations.test.js b/client/__tests__/e2e/e2eAnnotations.test.js
index 598bd771..14354033 100644
--- a/client/__tests__/e2e/e2eAnnotations.test.js
+++ b/client/__tests__/e2e/e2eAnnotations.test.js
@@ -39,6 +39,9 @@ import {
   removeGene,
   assertGeneDoesNotExist,
   expandGene,
+  colorByGeneset,
+  assertColorLegendLabel,
+  colorByGene,
 } from "./cellxgeneActions";
 
 const data = datasets[DATASET];
@@ -51,6 +54,7 @@ const genesetToDeleteName = "geneset_to_delete";
 const preExistingGenesetName = "fifth_dataset";
 const meanExpressionBrushGenesetName = "second_gene_set";
 const meanExpressionBrushCellsSelected = "557";
+const subsetMeanExpressionBrushCellsSelected = "452";
 
 // initial text, the text we type in, the result
 const editableGenesetName = "geneset_to_edit";
@@ -66,16 +70,19 @@ const geneToRemove = "SIK1";
 const setToRemoveFrom = "empty_this_geneset";
 
 // brush a gene
-const geneToBrush = "SIK1";
+const geneToBrushAndColorBy = "SIK1";
 const brushThisGeneGeneset = "brush_this_gene";
 const geneBrushedCellCount = "109";
+const subsetGeneBrushedCellCount = "96";
 
 async function setup(config) {
   await goToPage(appUrlBase);
 
-  // setup the test fixtures
-  await createCategory(perTestCategoryName);
-  await createLabel(perTestCategoryName, perTestLabelName);
+  if (config.categoricalAnno) {
+    // setup the test fixtures
+    await createCategory(perTestCategoryName);
+    await createLabel(perTestCategoryName, perTestLabelName);
+  }
 
   if (config.withSubset) {
     await subset({ x1: 0.1, y1: 0.1, x2: 0.8, y2: 0.8 });
@@ -84,14 +91,17 @@ async function setup(config) {
   await waitByClass("autosave-complete");
 }
 
-describe("geneSET crud operations and interactions", () => {
+describe.each([
+  { withSubset: true, tag: "subset" },
+  { withSubset: false, tag: "whole" },
+])("geneSET crud operations and interactions", (config) => {
   test("genesets load from csv", async () => {
-    await goToPage(appUrlBase);
+    await setup(config);
 
     await assertGenesetExists(preExistingGenesetName);
   });
   test("brush on geneset mean", async () => {
-    await goToPage(appUrlBase);
+    await setup(config);
 
     await expandGeneset(meanExpressionBrushGenesetName);
 
@@ -107,11 +117,22 @@ describe("geneSET crud operations and interactions", () => {
     await drag(histBrushableAreaId, coords.start, coords.end);
 
     const cellCount = await getCellSetCount(1);
+    if (config.withSubset) {
+      expect(cellCount).toBe(subsetMeanExpressionBrushCellsSelected);
+    } else {
+      expect(cellCount).toBe(meanExpressionBrushCellsSelected);
+    }
+  });
+  test("color by mean expression", async () => {
+    await setup(config);
 
-    expect(cellCount).toBe(meanExpressionBrushCellsSelected);
+    await colorByGeneset(meanExpressionBrushGenesetName);
+    await assertColorLegendLabel(meanExpressionBrushGenesetName);
   });
   test("create a new geneset", async () => {
-    await goToPage(appUrlBase);
+    if (config.withSubset) return;
+
+    await setup(config);
 
     const genesetName = `test-geneset-foo-123`;
     await assertGenesetDoesNotExist(genesetName);
@@ -120,31 +141,37 @@ describe("geneSET crud operations and interactions", () => {
     await assertGenesetExists(genesetName);
   });
   test("edit geneset name", async () => {
-    await goToPage(appUrlBase);
+    await setup(config);
 
     await editGenesetName(editableGenesetName, editText);
     await assertGenesetExists(newGenesetName);
   });
   test("delete a geneset", async () => {
-    await goToPage(appUrlBase);
+    if (config.withSubset) return;
+
+    await setup(config);
 
     await deleteGeneset(genesetToDeleteName);
   });
 });
 
-describe("GENE crud operations and interactions", () => {
+describe.each([
+  { withSubset: true, tag: "subset" },
+  { withSubset: false, tag: "whole" },
+])("GENE crud operations and interactions", (config) => {
   test("add a gene to geneset", async () => {
-    await goToPage(appUrlBase);
+    await setup(config);
 
     await addGeneToSet(setToAddGeneTo, geneToAddToSet);
     await expandGeneset(setToAddGeneTo);
     await assertGeneExistsInGeneset(geneToAddToSet);
   });
   test("expand gene and brush", async () => {
-    await goToPage(appUrlBase);
+    await setup(config);
+
     await expandGeneset(brushThisGeneGeneset);
-    await expandGene(geneToBrush);
-    const histBrushableAreaId = `histogram-${geneToBrush}-plot-brushable-area`;
+    await expandGene(geneToBrushAndColorBy);
+    const histBrushableAreaId = `histogram-${geneToBrushAndColorBy}-plot-brushable-area`;
 
     const coords = await calcDragCoordinates(histBrushableAreaId, {
       x1: 0.25,
@@ -154,10 +181,25 @@ describe("GENE crud operations and interactions", () => {
     });
     await drag(histBrushableAreaId, coords.start, coords.end);
     const cellCount = await getCellSetCount(1);
-    expect(cellCount).toBe(geneBrushedCellCount);
+    if (config.withSubset) {
+      expect(cellCount).toBe(subsetGeneBrushedCellCount);
+    } else {
+      expect(cellCount).toBe(geneBrushedCellCount);
+    }
+  });
+  test("color by gene in geneset", async () => {
+    await setup(config);
+
+    await expandGeneset(meanExpressionBrushGenesetName);
+
+    await colorByGene(geneToBrushAndColorBy);
+    await assertColorLegendLabel(geneToBrushAndColorBy);
   });
   test("delete gene from geneset", async () => {
-    await goToPage(appUrlBase);
+    // We've already deleted the gene
+    if (config.withSubset) return;
+
+    await setup(config);
 
     await expandGeneset(setToRemoveFrom);
     await removeGene(geneToRemove);
@@ -166,8 +208,8 @@ describe("GENE crud operations and interactions", () => {
 });
 
 describe.each([
-  { withSubset: true, tag: "subset" },
-  { withSubset: false, tag: "whole" },
+  { withSubset: true, tag: "subset", categoricalAnno: true },
+  { withSubset: false, tag: "whole", categoricalAnno: true },
 ])("annotations", (config) => {
   test("create a category", async () => {
     await setup(config);
diff --git a/client/src/components/continuousLegend/index.js b/client/src/components/continuousLegend/index.js
index 150cd8a4..a4d1f1d3 100644
--- a/client/src/components/continuousLegend/index.js
+++ b/client/src/components/continuousLegend/index.js
@@ -98,6 +98,8 @@ const continuous = (selectorId, colorScale, colorAccessor) => {
     .attr("y", 2)
     .attr("x", 0 - legendHeight / 2)
     .attr("dy", "1em")
+    .attr("data-testid", "continuous_legend_color_by_label")
+    .attr("aria-label", colorAccessor)
     .style("text-anchor", "middle")
     .style("fill", "white")
     .text(colorAccessor);