diff --git a/scripts/utils/theme/gnome_shell_theme_builder.py b/scripts/utils/theme/gnome_shell_theme_builder.py
index c51b0eb..5a6a586 100644
--- a/scripts/utils/theme/gnome_shell_theme_builder.py
+++ b/scripts/utils/theme/gnome_shell_theme_builder.py
@@ -4,11 +4,13 @@ from scripts import config
 from scripts.install.colors_definer import ColorsDefiner
 from scripts.utils.color_converter import ColorConverterImpl
 from scripts.utils.logger.console import Console
+from scripts.utils.style_manager import StyleManager
 from scripts.utils.theme.theme import Theme
 from scripts.utils.theme.theme_color_applier import ColorReplacementGenerator, ThemeColorApplier
 from scripts.utils.theme.theme_installer import ThemeInstaller
 from scripts.utils.theme.theme_path_provider import ThemePathProvider
 from scripts.utils.theme.theme_preparation import ThemePreparation
+from scripts.utils.theme.theme_temp_manager import ThemeTempManager
 from theme import SourceFolder
 
 
@@ -78,8 +80,12 @@ class GnomeShellThemeBuilder:
         return Theme(self.preparation, self.installer, self.mode, self.is_filled)
 
     def _resolve_preparation(self):
-        if self.preparation is None:
-            self.preparation = ThemePreparation(self.source_folder, self.temp_folder, self.main_styles)
+        if self.preparation is not None: return
+
+        file_manager = ThemeTempManager(self.temp_folder)
+        style_manager = StyleManager(self.main_styles)
+        self.preparation = ThemePreparation(self.source_folder,
+                                            file_manager=file_manager, style_manager=style_manager)
 
     def _resolve_installer(self):
         if self.installer is not None: return
diff --git a/scripts/utils/theme/theme_preparation.py b/scripts/utils/theme/theme_preparation.py
index fb7dedd..6d12c83 100644
--- a/scripts/utils/theme/theme_preparation.py
+++ b/scripts/utils/theme/theme_preparation.py
@@ -1,4 +1,5 @@
 import os
+import warnings
 
 from scripts.utils import replace_keywords
 from scripts.utils.theme.theme_temp_manager import ThemeTempManager
@@ -11,32 +12,49 @@ class ThemePreparation:
     and preparing them for installation.
     """
 
-    def __init__(self, sources_location: str, temp_folder: str, combined_styles_location: str):
+    def __init__(self, sources_location: str, file_manager: ThemeTempManager, style_manager: StyleManager):
         self.sources_location = sources_location
-        self.temp_folder = temp_folder
-        self.combined_styles_location = combined_styles_location
 
-        self.file_manager = ThemeTempManager(temp_folder)
-        self.style_manager = StyleManager(combined_styles_location)
+        self.file_manager = file_manager
+        self.style_manager = style_manager
+
+    @property
+    def temp_folder(self):
+        return self.file_manager.temp_folder
+
+    @property
+    def combined_styles_location(self):
+        return self.style_manager.output_file
 
     def __add__(self, content: str) -> "ThemePreparation":
+        """Append additional styles to the main styles file."""
         self.style_manager.append_content(content)
         return self
 
     def __mul__(self, content: str) -> "ThemePreparation":
+        """Adds a file to the theme, copying it to the temporary folder."""
         self.file_manager.copy_to_temp(content)
         return self
 
     def add_to_start(self, content) -> "ThemePreparation":
+        """Inserts content at the beginning of the main styles file."""
         self.style_manager.prepend_content(content)
         return self
 
     def prepare(self):
+        """
+        Extract theme from source folder and prepare it for installation.
+        """
         self.file_manager.prepare_files(self.sources_location)
         self.style_manager.generate_combined_styles(self.sources_location, self.temp_folder)
         self.file_manager.cleanup()
 
+    @warnings.deprecated
     def replace_filled_keywords(self):
+        """
+        Replace keywords in the theme files for filled mode.
+        This method is deprecated and will be removed in future versions.
+        """
         for apply_file in os.listdir(f"{self.temp_folder}/"):
             replace_keywords(f"{self.temp_folder}/{apply_file}",
                              ("BUTTON-COLOR", "ACCENT-FILLED-COLOR"),