diff --git a/CotEditor/Sources/LayoutManager.swift b/CotEditor/Sources/LayoutManager.swift
index b1e7f8b211..b034dd65d0 100644
--- a/CotEditor/Sources/LayoutManager.swift
+++ b/CotEditor/Sources/LayoutManager.swift
@@ -173,9 +173,11 @@ class LayoutManager: NSLayoutManager, InvisibleDrawing, ValidationIgnorable, Lin
         if color == .unemphasizedSelectedContentBackgroundColor,  // check if inactive
            let textView = self.textContainer(forGlyphAt: self.glyphIndexForCharacter(at: charRange.location),
                                              effectiveRange: nil, withoutAdditionalLayout: true)?.textView,
-           let theme = (textView as? any Themable)?.theme
+           let theme = (textView as? any Themable)?.theme,
+           let newColor = theme.effectiveSecondarySelectionColor(for: textView.effectiveAppearance),
+           newColor != color
         {
-            theme.effectiveSecondarySelectionColor(for: textView.effectiveAppearance)?.setFill()
+            newColor.setFill()
         }
         
         super.fillBackgroundRectArray(rectArray, count: rectCount, forCharacterRange: charRange, color: color)
diff --git a/CotEditor/Sources/Theme.swift b/CotEditor/Sources/Theme.swift
index 609b40c720..1b3962c73e 100644
--- a/CotEditor/Sources/Theme.swift
+++ b/CotEditor/Sources/Theme.swift
@@ -182,9 +182,9 @@ struct Theme: Equatable {
         
         if self.selection.usesSystemSetting {
             return if self.isDarkTheme == appearance.isDark {
-                .unemphasizedSelectedTextBackgroundColor
+                .unemphasizedSelectedContentBackgroundColor
             } else {
-                .unemphasizedSelectedTextBackgroundColor.solve(for: appearance.appearance(for: self.isDarkTheme))
+                .unemphasizedSelectedContentBackgroundColor.solve(for: appearance.appearance(for: self.isDarkTheme))
             }
         } else {
             guard let color = self.selection.color.usingColorSpace(.genericRGB) else { return nil }
diff --git a/Tests/ThemeTests.swift b/Tests/ThemeTests.swift
index ec558d3e0f..ba238828e2 100644
--- a/Tests/ThemeTests.swift
+++ b/Tests/ThemeTests.swift
@@ -9,7 +9,7 @@
 //
 //  ---------------------------------------------------------------------------
 //
-//  © 2016-2023 1024jp
+//  © 2016-2024 1024jp
 //
 //  Licensed under the Apache License, Version 2.0 (the "License");
 //  you may not use this file except in compliance with the License.
@@ -46,7 +46,7 @@ final class ThemeTests: XCTestCase {
         XCTAssertEqual(theme.invisibles.color.brightnessComponent, 0.72, accuracy: 0.01)
         XCTAssertEqual(theme.background.color, NSColor.white.usingColorSpace(.genericRGB))
         XCTAssertEqual(theme.lineHighlight.color.brightnessComponent, 0.94, accuracy: 0.01)
-        XCTAssertNil(theme.secondarySelectionColor)
+        XCTAssertEqual(theme.effectiveSecondarySelectionColor(for: NSAppearance(named: .aqua)!), .unemphasizedSelectedContentBackgroundColor)
         XCTAssertFalse(theme.isDarkTheme)
         
         for type in SyntaxType.allCases {