diff --git a/docs/developers-guide.md b/docs/developers-guide.md
index b863f0c3f..4ae5442c4 100644
--- a/docs/developers-guide.md
+++ b/docs/developers-guide.md
@@ -219,7 +219,7 @@ PluginRegistry.add('themes', {
     'tertiary-color-lightness': '33.5%',
     // A color used for the font/svg icons when placed on a primary color background.
     'icon-on-primary-color': 'rgba(255, 255, 255, 0.8)',
-    'grey-color': '#97999C',
+    'gray-color': '#97999C',
     // Colors for the toastr notifications in any of their four states.
     'color-danger-dark': '#a41424',
     'color-success-dark': '#005934',
diff --git a/src/css/clustermanagement.css b/src/css/clustermanagement.css
index 2c8367f8e..bb66e9ce2 100644
--- a/src/css/clustermanagement.css
+++ b/src/css/clustermanagement.css
@@ -47,7 +47,7 @@ path.link {
 
 .node {
   cursor: pointer;
-  fill: var(--grey-color);
+  fill: var(--gray-color);
   stroke: black;
 }
 
@@ -64,7 +64,7 @@ path.link {
 }
 
 .node.other {
-  fill: var(--grey-color)
+  fill: var(--gray-color)
 }
 
 #node-group.legend .node {
diff --git a/src/js/angular/clustermanagement/cluster-drawing.service.js b/src/js/angular/clustermanagement/cluster-drawing.service.js
index 5cf028437..1dad6c00c 100644
--- a/src/js/angular/clustermanagement/cluster-drawing.service.js
+++ b/src/js/angular/clustermanagement/cluster-drawing.service.js
@@ -4,7 +4,7 @@ export const clusterColors = {
     ontoOrange: 'var(--primary-color)',
     ontoBlue: 'var(--secondary-color)',
     ontoGreen: 'var(--tertiary-color)',
-    ontoGrey: 'var(--grey-color)'
+    ontoGrey: 'var(--gray-color)'
 };
 
 export function createClusterSvgElement(element) {
diff --git a/src/js/angular/core/services/theme-service.js b/src/js/angular/core/services/theme-service.js
index 1ab5583e3..cbb59b5f4 100644
--- a/src/js/angular/core/services/theme-service.js
+++ b/src/js/angular/core/services/theme-service.js
@@ -22,7 +22,7 @@ const ThemeDefinitionModel = {
     'tertiary-color-saturation': null,
     'tertiary-color-lightness': null,
     'icon-on-primary-color': null,
-    'grey-color': null,
+    'gray-color': null,
     'color-danger-dark': null,
     'color-success-dark': null,
     'color-warning-dark': null,
@@ -213,7 +213,7 @@ function ThemeService(workbenchSettingsStorageService, $translate, toastr) {
 
                 --icon-on-primary-color: ${themeDefinition['icon-on-primary-color']};
 
-                --grey-color: ${themeDefinition['grey-color']};
+                --gray-color: ${themeDefinition['gray-color']};
 
                 --color-danger-dark: ${themeDefinition['color-danger-dark']};
                 --color-success-dark: ${themeDefinition['color-success-dark']};
diff --git a/src/themes/default/plugin.js b/src/themes/default/plugin.js
index 887d2fc9a..8939cd877 100644
--- a/src/themes/default/plugin.js
+++ b/src/themes/default/plugin.js
@@ -18,7 +18,7 @@ PluginRegistry.add('themes', {
     'tertiary-color-lightness': '33.5%',
     // A color used for the font/svg icons when placed on a primary color background.
     'icon-on-primary-color': 'rgba(255, 255, 255, 0.8)',
-    'grey-color': '#97999C',
+    'gray-color': '#97999C',
     // Colors for the toastr notifications in any of their four states.
     'color-danger-dark': '#a41424',
     'color-success-dark': '#005934',
diff --git a/src/themes/onto-original/plugin.js b/src/themes/onto-original/plugin.js
index 54aff41ca..841c0524a 100644
--- a/src/themes/onto-original/plugin.js
+++ b/src/themes/onto-original/plugin.js
@@ -11,7 +11,7 @@ PluginRegistry.add('themes', {
     'tertiary-color-saturation': '97.7%',
     'tertiary-color-lightness': '33.5%',
     'icon-on-primary-color': 'rgba(255, 255, 255, 0.8)',
-    'grey-color': '#97999C',
+    'gray-color': '#97999C',
     'color-danger-dark': '#bd362f',
     'color-success-dark': '#51a351',
     'color-warning-dark': '#f89406',