diff --git a/plugin/package.json b/plugin/package.json
index 9c42ada0c..958571c82 100644
--- a/plugin/package.json
+++ b/plugin/package.json
@@ -8,7 +8,7 @@
   "scripts": {
     "dev": "webpack --config webpack.dev.js",
     "prod": "webpack --config webpack.prod.js",
-    "start": "yarn dev -- --watch",
+    "start": "yarn dev --watch",
     "lint:js": "eslint src/main/js --ext js",
     "mvnbuild": "yarn prod",
     "mvntest": "yarn lint:js"
diff --git a/plugin/pom.xml b/plugin/pom.xml
index 4c79749ee..e3d9cf973 100644
--- a/plugin/pom.xml
+++ b/plugin/pom.xml
@@ -191,17 +191,6 @@
                 </exclusion>
             </exclusions>
         </dependency>
-        <dependency>
-            <groupId>io.jenkins.plugins</groupId>
-            <artifactId>theme-manager</artifactId>
-            <optional>true</optional>
-            <exclusions>
-                <exclusion>
-                    <groupId>io.jenkins.blueocean</groupId>
-                    <artifactId>blueocean-web</artifactId>
-                </exclusion>
-            </exclusions>
-        </dependency>
         <dependency>
             <groupId>org.jenkins-ci.plugins</groupId>
             <artifactId>scm-api</artifactId>
diff --git a/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition.java b/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition.java
index 88b787089..eea31e59e 100644
--- a/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition.java
+++ b/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition.java
@@ -37,21 +37,16 @@
 import net.sf.json.JSONObject;
 import org.apache.commons.lang.StringUtils;
 import org.jenkinsci.plugins.workflow.cps.persistence.PersistIn;
-import org.jenkinsci.plugins.workflow.cps.replay.ReplayAction;
-import org.jenkinsci.plugins.workflow.cps.view.ThemeUtil;
 import org.jenkinsci.plugins.workflow.flow.DurabilityHintProvider;
 import org.jenkinsci.plugins.workflow.flow.FlowDefinition;
 import org.jenkinsci.plugins.workflow.flow.FlowDefinitionDescriptor;
 import org.jenkinsci.plugins.workflow.flow.FlowDurabilityHint;
 import org.jenkinsci.plugins.workflow.flow.FlowExecutionOwner;
 import org.jenkinsci.plugins.workflow.flow.GlobalDefaultFlowDurabilityLevel;
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.DoNotUse;
 import org.kohsuke.stapler.AncestorInPath;
 import org.kohsuke.stapler.DataBoundConstructor;
 
 import java.io.IOException;
-import java.util.Arrays;
 import java.util.List;
 
 import net.sf.json.JSON;
@@ -184,10 +179,4 @@ public JSON doCheckScriptCompile(@AncestorInPath Item job, @QueryParameter Strin
         }
 
     }
-
-    /** @see ReplayAction#getTheme */
-    @Restricted(DoNotUse.class)
-    /* accessible to Jelly */ public String getTheme() {
-        return ThemeUtil.getTheme();
-    }
 }
diff --git a/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/replay/ReplayAction.java b/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/replay/ReplayAction.java
index ce718728a..a92696abe 100644
--- a/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/replay/ReplayAction.java
+++ b/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/replay/ReplayAction.java
@@ -70,7 +70,6 @@
 import org.acegisecurity.AccessDeniedException;
 import org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition;
 import org.jenkinsci.plugins.workflow.cps.CpsFlowExecution;
-import org.jenkinsci.plugins.workflow.cps.view.ThemeUtil;
 import org.jenkinsci.plugins.workflow.flow.FlowExecution;
 import org.jenkinsci.plugins.workflow.flow.FlowExecutionOwner;
 import org.kohsuke.accmod.Restricted;
@@ -200,12 +199,6 @@ private ReplayAction(Run run) {
         return run;
     }
 
-    /** @see CpsFlowDefinition#getTheme */
-    @Restricted(DoNotUse.class)
-    /* accessible to Jelly */ public String getTheme() {
-        return ThemeUtil.getTheme();
-    }
-
     @Restricted(DoNotUse.class)
     @RequirePOST
     public void doRun(StaplerRequest req, StaplerResponse rsp) throws ServletException, IOException {
diff --git a/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/view/ThemeUtil.java b/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/view/ThemeUtil.java
deleted file mode 100644
index eaf91e77c..000000000
--- a/plugin/src/main/java/org/jenkinsci/plugins/workflow/cps/view/ThemeUtil.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package org.jenkinsci.plugins.workflow.cps.view;
-
-import io.jenkins.plugins.thememanager.Theme;
-import io.jenkins.plugins.thememanager.ThemeManagerPageDecorator;
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
-
-@Restricted(NoExternalUse.class)
-public final class ThemeUtil {
-
-    private ThemeUtil() {
-        // Suppress default constructor for noninstantiability
-        throw new AssertionError();
-    }
-
-    public static String getTheme() {
-        try {
-            Theme theme = ThemeManagerPageDecorator.get().findTheme();
-            return theme.getProperty("ace-editor", "theme").orElse("tomorrow");
-        } catch (LinkageError e) {
-            // Optional plugin not installed
-            return "tomorrow";
-        }
-    }
-}
diff --git a/plugin/src/main/js/workflow-editor.js b/plugin/src/main/js/workflow-editor.js
index 7a8f5842f..81da7098c 100644
--- a/plugin/src/main/js/workflow-editor.js
+++ b/plugin/src/main/js/workflow-editor.js
@@ -16,6 +16,11 @@ import "./snippets/workflow";
 
 var editorIdCounter = 0;
 
+function setTheme(editor) {
+    const theme = window.getThemeManagerProperty('ace-editor', 'theme') || 'tomorrow'
+    editor.setTheme("ace/theme/" + theme);
+}
+
 $(function() {
         $('.workflow-editor-wrapper').each(function() {
             initEditor($(this));
@@ -44,10 +49,17 @@ $(function() {
                 var snippetContent = ace.require('ace/snippets/groovy').snippetText;
                 var snippets = snippetManager.parseSnippetFile(snippetContent);
                 snippetManager.register(snippets, 'groovy');
-
                     editor.session.setMode("ace/mode/groovy");
-                    var theme = aceContainer.attr("theme") === "tomorrow_night" ? "tomorrow_night" : "tomorrow";
-                    editor.setTheme("ace/theme/" + theme);
+                    if (window.getThemeManagerProperty) {
+                        setTheme(editor);
+
+                        if (window.isSystemRespectingTheme) {
+                            window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', event => {
+                                setTheme(editor)
+                            });
+                        }
+
+                    }
                     editor.setAutoScrollEditorIntoView(true);
                     editor.setOption("minLines", 20);
                     // enable autocompletion and snippets
diff --git a/plugin/src/main/resources/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition/config.jelly b/plugin/src/main/resources/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition/config.jelly
index 6be9df79c..c075a1fd2 100644
--- a/plugin/src/main/resources/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition/config.jelly
+++ b/plugin/src/main/resources/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition/config.jelly
@@ -26,7 +26,7 @@
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form" xmlns:st="jelly:stapler" xmlns:wfe="/org/jenkinsci/plugins/workflow/editor">
   <input type="hidden" name="oldScript" value="${instance.script}"/>
   <f:entry title="${%Script}" field="script">
-    <wfe:workflow-editor theme="${instance.theme}" />
+    <wfe:workflow-editor />
   </f:entry>
   <f:entry field="sandbox">
     <f:checkbox title="${%Use Groovy Sandbox}" default="true"/>
diff --git a/plugin/src/main/resources/org/jenkinsci/plugins/workflow/editor/workflow-editor.jelly b/plugin/src/main/resources/org/jenkinsci/plugins/workflow/editor/workflow-editor.jelly
index 62f424ff6..ff266c184 100644
--- a/plugin/src/main/resources/org/jenkinsci/plugins/workflow/editor/workflow-editor.jelly
+++ b/plugin/src/main/resources/org/jenkinsci/plugins/workflow/editor/workflow-editor.jelly
@@ -5,9 +5,6 @@
         <st:attribute name="script">
             The script.
         </st:attribute>
-        <st:attribute name="theme">
-            The ACE editor theme.
-        </st:attribute>
     </st:documentation>
     <j:choose>
         <j:when test="${h.isUnitTest}">
@@ -17,7 +14,7 @@
         <j:otherwise>
             <div class="workflow-editor-wrapper" style="display: none; position: relative">
                 <f:textarea value="${script}" checkMethod="post" checkUrl="${attrs.checkUrl}" checkDependsOn="${attrs.checkDependsOn}"/>
-                <div class="pane-frame editor" style="height: 250px;" samplesUrl="${rootURL}/workflow-cps-samples/" theme="${theme ?: 'tomorrow'}"/>
+                <div class="pane-frame editor" style="height: 250px;" samplesUrl="${rootURL}/workflow-cps-samples/" />
             </div>
             <st:adjunct includes="org.jenkinsci.plugins.workflow.cps.workflow-editor"/>
         </j:otherwise>