diff --git a/client/src/components/geneExpression/geneSet.js b/client/src/components/geneExpression/geneSet.js
index aeb359ca..b0a649ed 100644
--- a/client/src/components/geneExpression/geneSet.js
+++ b/client/src/components/geneExpression/geneSet.js
@@ -179,7 +179,12 @@ class GeneSet extends React.Component {
             )}
           </span>
           <div>
-            <GenesetMenus genesetsEditable geneset={setName} />
+            <GenesetMenus
+              isOpen={isOpen}
+              toggleSummaryHisto={toggleSummaryHisto}
+              genesetsEditable
+              geneset={setName}
+            />
           </div>
         </div>
 
diff --git a/client/src/components/geneExpression/menus/genesetMenus.js b/client/src/components/geneExpression/menus/genesetMenus.js
index 7f48948d..d7b7b6b3 100644
--- a/client/src/components/geneExpression/menus/genesetMenus.js
+++ b/client/src/components/geneExpression/menus/genesetMenus.js
@@ -1,12 +1,14 @@
 import React from "react";
 import { connect } from "react-redux";
+import { Tooltip2 } from "@blueprintjs/popover2";
+
 import {
   Button,
+  AnchorButton,
   Menu,
   MenuItem,
   Popover,
   Position,
-  Tooltip,
   Icon,
   PopoverInteractionKind,
 } from "@blueprintjs/core";
@@ -18,6 +20,7 @@ import AddGeneToGenesetDialogue from "./addGeneToGenesetDialogue";
 @connect((state) => {
   return {
     genesetsUI: state.genesetsUI,
+    colorAccessor: state.colors.colorAccessor,
   };
 })
 class GenesetMenus extends React.PureComponent {
@@ -43,19 +46,41 @@ class GenesetMenus extends React.PureComponent {
     });
   };
 
+  handleColorByEntireGeneset = () => {
+    const { dispatch, geneset } = this.props;
+
+    dispatch({
+      type: "color by geneset mean expression",
+      geneset,
+    });
+  };
+
   handleDeleteCategory = () => {
     const { dispatch, geneset } = this.props;
     dispatch(actions.genesetDelete(geneset));
   };
 
   render() {
-    const { geneset, genesetsEditable, createText } = this.props;
+    const {
+      geneset,
+      genesetsEditable,
+      createText,
+      colorAccessor,
+      isOpen,
+      toggleSummaryHisto,
+    } = this.props;
+
+    const isColorBy = geneset === colorAccessor;
+    const genesetClosed = !isOpen;
+    const showingAllGenes = !toggleSummaryHisto;
+
+    const notShowingSummary = genesetClosed || showingAllGenes;
 
     return (
       <>
         {genesetsEditable ? (
           <>
-            <Tooltip
+            <Tooltip2
               content={createText}
               position={Position.BOTTOM}
               hoverOpenDelay={globals.tooltipHoverOpenDelay}
@@ -69,7 +94,7 @@ class GenesetMenus extends React.PureComponent {
                 small
                 minimal
               />
-            </Tooltip>
+            </Tooltip2>
             <AddGeneToGenesetDialogue geneset={geneset} />
             <Popover
               interactionKind={PopoverInteractionKind.HOVER}
@@ -104,13 +129,22 @@ class GenesetMenus extends React.PureComponent {
                 minimal
               />
             </Popover>
-            <Button
-              disabled
-              style={{ marginLeft: 0 }}
-              data-testclass="colorby-entire-geneset"
-              data-testid={`${geneset}:colorby-entire-geneset`}
-              icon={<Icon icon="tint" iconSize={16} />}
-            />
+            <Tooltip2
+              content={`Color by gene set ${geneset} mean (gene set must be open, and toggled to mean expression histogram)`}
+              position={Position.BOTTOM}
+              hoverOpenDelay={globals.tooltipHoverOpenDelay}
+            >
+              <AnchorButton
+                disabled={notShowingSummary && !isColorBy}
+                active={isColorBy}
+                intent={isColorBy ? "primary" : "none"}
+                style={{ marginLeft: 0 }}
+                onClick={this.handleColorByEntireGeneset}
+                data-testclass="colorby-entire-geneset"
+                data-testid={`${geneset}:colorby-entire-geneset`}
+                icon={<Icon icon="tint" iconSize={16} />}
+              />
+            </Tooltip2>
           </>
         ) : null}
       </>
diff --git a/client/src/reducers/colors.js b/client/src/reducers/colors.js
index a95b51ce..39d021a1 100644
--- a/client/src/reducers/colors.js
+++ b/client/src/reducers/colors.js
@@ -4,8 +4,8 @@ Color By UI state
 
 const ColorsReducer = (
   state = {
-    colorMode: null,
-    colorAccessor: null,
+    colorMode: null /* by continuous, by expression */,
+    colorAccessor: null /* tissue, Apod */,
   },
   action,
   nextSharedState,
@@ -96,6 +96,21 @@ const ColorsReducer = (
       };
     }
 
+    case "color by geneset mean expression": {
+      /* toggle between this mode and reset */
+      const resetCurrent =
+        action.type === state.colorMode &&
+        action.geneset === state.colorAccessor;
+      const colorMode = !resetCurrent ? action.type : null;
+      const colorAccessor = !resetCurrent ? action.geneset : null;
+
+      return {
+        ...state,
+        colorMode,
+        colorAccessor,
+      };
+    }
+
     default: {
       return state;
     }