[JENKINS-34019] When displaying timestamps, ignore AnsiColor plugin s…

…tyling

src/main/java/hudson/plugins/timestamper/annotator/TimestampAnnotatorFactory2.java

@@ -122,6 +122,14 @@ public boolean hasScript() {
     return true;
   }
 
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  public boolean hasStylesheet() {
+    return true;
+  }
+
   /**
    * {@inheritDoc}
    */
@@ -146,6 +154,20 @@ public void doScriptJs(StaplerRequest req, StaplerResponse rsp)
     rsp.setHeader(HttpHeaders.LOCATION, ResponseImpl.encode(url));
   }
 
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  @WebMethod(name = "style.css")
+  public void doStyleCss(StaplerRequest req, StaplerResponse rsp)
+      throws IOException, ServletException {
+    // See the comments in doScriptJs for more details.
+    String url = req.getContextPath() + getResourcePath()
+        + "/plugin/timestamper/style.css";
+    rsp.setStatus(HttpServletResponse.SC_MOVED_TEMPORARILY);
+    rsp.setHeader(HttpHeaders.LOCATION, ResponseImpl.encode(url));
+  }
+
   private String getResourcePath() {
     Jenkins jenkins = Jenkins.getInstance();
     if (jenkins != null) {

src/main/webapp/style.css

@@ -0,0 +1,8 @@
+
+/* Override style changes made by the AnsiColor plugin. */
+.timestamp {
+  color: #333;
+  background-color: white;
+  font-weight: normal;
+  display: inline-block;
+}