diff --git a/platform/lang-impl/src/com/intellij/ide/impl/StructureViewWrapperImpl.kt b/platform/lang-impl/src/com/intellij/ide/impl/StructureViewWrapperImpl.kt
index 9de6d1be972f..2468c59a5a51 100644
--- a/platform/lang-impl/src/com/intellij/ide/impl/StructureViewWrapperImpl.kt
+++ b/platform/lang-impl/src/com/intellij/ide/impl/StructureViewWrapperImpl.kt
@@ -56,6 +56,7 @@ import com.intellij.util.PlatformUtils
 import com.intellij.util.cancelOnDispose
 import com.intellij.util.concurrency.AppExecutorUtil
 import com.intellij.util.messages.Topic
+import com.intellij.util.ui.JBUI
 import com.intellij.util.ui.TimerUtil
 import com.intellij.util.ui.UIUtil
 import kotlinx.coroutines.*
@@ -480,7 +481,7 @@ class StructureViewWrapperImpl(
       if (myModuleStructureComponent == null && myStructureView == null) {
         val panel: JBPanelWithEmptyText = object : JBPanelWithEmptyText() {
           override fun getBackground(): Color {
-            return UIUtil.getTreeBackground()
+            return JBUI.CurrentTheme.ToolWindow.background()
           }
         }
         panel.emptyText.setText(LangBundle.message("panel.empty.text.no.structure"))
@@ -548,7 +549,7 @@ class StructureViewWrapperImpl(
 
   private fun createContentPanel(component: JComponent): ContentPanel {
     val panel = ContentPanel()
-    panel.background = UIUtil.getTreeBackground()
+    panel.background = JBUI.CurrentTheme.ToolWindow.background()
     panel.add(component, BorderLayout.CENTER)
     return panel
   }
diff --git a/platform/platform-impl/src/com/intellij/openapi/application/impl/islands/IslandsRoundedBorder.kt b/platform/platform-impl/src/com/intellij/openapi/application/impl/islands/IslandsRoundedBorder.kt
index 11735354bd2a..edc88816b597 100644
--- a/platform/platform-impl/src/com/intellij/openapi/application/impl/islands/IslandsRoundedBorder.kt
+++ b/platform/platform-impl/src/com/intellij/openapi/application/impl/islands/IslandsRoundedBorder.kt
@@ -25,7 +25,7 @@ internal class IslandsRoundedBorder(fillColor: (JComponent) -> Paint?) :
 
   companion object {
     fun createToolWindowBorder(component: JComponent) {
-      component.border = IslandsRoundedBorder { JBUI.CurrentTheme.ToolWindow.background() }
+      component.border = IslandsRoundedBorder { it.background }
     }
 
     fun createEditorBorder(editorsSplitters: EditorsSplitters, editorTabPainter: TabPainterAdapter) {
diff --git a/platform/platform-impl/src/com/intellij/openapi/application/impl/islands/IslandsUICustomization.kt b/platform/platform-impl/src/com/intellij/openapi/application/impl/islands/IslandsUICustomization.kt
index c769405e1870..7b2f76d9af44 100644
--- a/platform/platform-impl/src/com/intellij/openapi/application/impl/islands/IslandsUICustomization.kt
+++ b/platform/platform-impl/src/com/intellij/openapi/application/impl/islands/IslandsUICustomization.kt
@@ -61,9 +61,10 @@ internal class IslandsUICustomization : InternalUICustomization() {
   override val shouldPaintEditorFadeout: Boolean = !isIslandsEnabled
 
   private val toolWindowDecorator = object : ToolWindowUIDecorator() {
-    override fun decorateAndReturnHolder(divider: JComponent, child: JComponent): JComponent? {
+    override fun decorateAndReturnHolder(divider: JComponent, child: JComponent): JComponent {
       return XNextIslandHolder().apply {
         layout = BorderLayout()
+        background = JBUI.CurrentTheme.ToolWindow.background()
         add(divider, BorderLayout.NORTH)
         add(child, BorderLayout.CENTER)
 
diff --git a/plugins/ide-features-trainer/src/training/ui/UISettings.kt b/plugins/ide-features-trainer/src/training/ui/UISettings.kt
index 88b66955ea93..8d7ddfeb26a9 100644
--- a/plugins/ide-features-trainer/src/training/ui/UISettings.kt
+++ b/plugins/ide-features-trainer/src/training/ui/UISettings.kt
@@ -53,7 +53,7 @@ internal class UISettings {
   val inactiveColor: Color = defaultTextColor.addAlpha(transparencyInactiveFactor)
   val moduleProgressColor: Color = JBColor.namedColor("Label.infoForeground", 0x808080, 0x8C8C8C)
   val shortcutSeparatorColor: Color = moduleProgressColor
-  val backgroundColor: Color = UIUtil.getTreeBackground()
+  val backgroundColor: Color = JBUI.CurrentTheme.ToolWindow.background()
   val completedColor: Color = UIUtil.getLabelSuccessForeground()
   val activeTaskBorder: Color = JBColor.namedColor("Component.focusColor", 0x97C3F3, 0x3D6185)