diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 8b35f3d1..0192d759 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -19,6 +19,7 @@ if(${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang")
 elseif(${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++1y")
 elseif(${CMAKE_CXX_COMPILER_ID} STREQUAL "MSVC")
+    add_definitions(-DUNICODE -D_UNICODE)
 endif()
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/../lib)
diff --git a/cmake/xlnt.test.cmake b/cmake/xlnt.test.cmake
index a92abce4..2ea886fc 100644
--- a/cmake/xlnt.test.cmake
+++ b/cmake/xlnt.test.cmake
@@ -17,6 +17,10 @@ source_group(helpers FILES ${TEST_HELPERS_HEADERS} ${TEST_HELPERS_SOURCES})
 
 target_link_libraries(xlnt.test xlnt)
 
+if(${CMAKE_CXX_COMPILER_ID} STREQUAL "MSVC")
+    target_link_libraries(xlnt.test Shlwapi)
+endif()
+
 add_custom_target (generate-test-runner
     COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/generate-tests
     COMMENT "Generating test runner tests/runner-autogen.cpp"
@@ -24,9 +28,11 @@ add_custom_target (generate-test-runner
 
 add_dependencies(xlnt.test generate-test-runner)
 
-add_custom_command(
-  TARGET xlnt.test
-  POST_BUILD
-  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/../bin/xlnt.test
-  VERBATIM
-)
+if(${CMAKE_GENERATOR} STREQUAL "Unix Makefiles")
+  add_custom_command(
+    TARGET xlnt.test
+    POST_BUILD
+    COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/../bin/xlnt.test
+    VERBATIM
+  )
+endif()
diff --git a/configure b/configure
index d0ce9c7a..6f3f5aef 100755
--- a/configure
+++ b/configure
@@ -33,7 +33,7 @@ if len(sys.argv) > 1:
 elif sys.platform == 'darwin':
    generator = 'Unix Makefiles'
 elif sys.platform == 'win32':
-   generator = 'Visual Studio 14 2015'
+   generator = 'Visual Studio 14 2015 Win64'
 
 cmake = 'cmake'
 
diff --git a/include/xlnt/styles/font.hpp b/include/xlnt/styles/font.hpp
index 21b35c0b..b0da3a2f 100644
--- a/include/xlnt/styles/font.hpp
+++ b/include/xlnt/styles/font.hpp
@@ -147,29 +147,17 @@ class font
 
     std::size_t hash() const
     {
-        std::size_t seed = bold_;
-        seed = seed << 1 & italic_;
-        seed = seed << 1 & superscript_;
-        seed = seed << 1 & subscript_;
-        seed = seed << 1 & strikethrough_;
-        
+        std::size_t seed = 0;
+
+		hash_combine(seed, bold_);
+		hash_combine(seed, italic_);
+		hash_combine(seed, superscript_);
+		hash_combine(seed, subscript_);
+		hash_combine(seed, strikethrough_);
         hash_combine(seed, name_);
         hash_combine(seed, size_);
         hash_combine(seed, static_cast<std::size_t>(underline_));
-        hash_combine(seed, static_cast<std::size_t>(color_.get_type()));
-        
-        switch (color_.get_type())
-        {
-        case color::type::indexed:
-            hash_combine(seed, color_.get_index());
-            break;
-        case color::type::theme:
-            hash_combine(seed, color_.get_theme());
-            break;
-        default:
-            break;
-        }
-        
+		hash_combine(seed, color_.hash());
         hash_combine(seed, family_);
         hash_combine(seed, scheme_);
 
diff --git a/include/xlnt/workbook/workbook.hpp b/include/xlnt/workbook/workbook.hpp
index 5d097642..a4f87f4f 100644
--- a/include/xlnt/workbook/workbook.hpp
+++ b/include/xlnt/workbook/workbook.hpp
@@ -212,16 +212,16 @@ class workbook
     void add_number_format(const number_format &format);
     void add_protection(const protection &p);
 
-    std::vector<style> get_styles() const;
+    const std::vector<style> &get_styles() const;
 
-    std::vector<color> get_colors() const;
-    std::vector<border> get_borders() const;
-    std::vector<fill> get_fills() const;
-    std::vector<font> get_fonts() const;
-    std::vector<number_format> get_number_formats() const;
+    const std::vector<color> &get_colors() const;
+    const std::vector<border> &get_borders() const;
+    const std::vector<fill> &get_fills() const;
+    const std::vector<font> &get_fonts() const;
+    const std::vector<number_format> &get_number_formats() const;
 
-    std::size_t add_indexed_color(const std::string &rgb);
-    std::string get_indexed_color(std::size_t color_index) const;
+    color add_indexed_color(const color &rgb_color);
+    color get_indexed_color(const color &indexed_color) const;
 
     const number_format &get_number_format(std::size_t style_id) const;
     std::size_t set_number_format(const number_format &format, std::size_t style_id);
diff --git a/source/common/datetime.cpp b/source/common/datetime.cpp
index 5d665776..e1c977c1 100644
--- a/source/common/datetime.cpp
+++ b/source/common/datetime.cpp
@@ -3,6 +3,22 @@
 
 #include <xlnt/common/datetime.hpp>
 
+namespace {
+
+std::tm safe_localtime(std::time_t raw_time)
+{
+#ifdef _MSC_VER
+	std::tm result;
+	localtime_s(&result, &raw_time);
+
+	return result;
+#else
+	return *localtime(&raw_time);
+#endif
+}
+
+} // namespace
+
 namespace xlnt {
 
 time time::from_number(long double raw_time)
@@ -163,15 +179,15 @@ std::string datetime::to_string(xlnt::calendar /*base_date*/) const
 
 date date::today()
 {
-    std::time_t raw_time = std::time(0);
-    std::tm now = *std::localtime(&raw_time);
+    std::tm now = safe_localtime(std::time(0));
+
     return date(1900 + now.tm_year, now.tm_mon + 1, now.tm_mday);
 }
 
 datetime datetime::now()
 {
-    std::time_t raw_time = std::time(0);
-    std::tm now = *std::localtime(&raw_time);
+	std::tm now = safe_localtime(std::time(0));
+
     return datetime(1900 + now.tm_year, now.tm_mon + 1, now.tm_mday, now.tm_hour, now.tm_min, now.tm_sec);
 }
 
diff --git a/source/serialization/comment_serializer.cpp b/source/serialization/comment_serializer.cpp
index 42760cf5..d36cd54a 100644
--- a/source/serialization/comment_serializer.cpp
+++ b/source/serialization/comment_serializer.cpp
@@ -1,5 +1,9 @@
 #include <xlnt/serialization/comment_serializer.hpp>
 
-namespace {
+namespace xlnt {
+
+comment_serializer::comment_serializer(worksheet sheet) : sheet_(sheet)
+{
+}
 
 } // namespace xlnt
diff --git a/source/serialization/excel_serializer.cpp b/source/serialization/excel_serializer.cpp
index 26298832..46062476 100644
--- a/source/serialization/excel_serializer.cpp
+++ b/source/serialization/excel_serializer.cpp
@@ -90,11 +90,10 @@ bool load_workbook(xlnt::zip_file &archive, bool guess_types, bool data_only, xl
 
     if(archive.has_file(xlnt::constants::ArcSharedString()))
     {
-        xlnt::shared_strings_serializer shared_strings_serializer_;
         std::vector<std::string> shared_strings;
 		xlnt::xml_document shared_strings_xml;
 		shared_strings_xml.from_string(archive.read(xlnt::constants::ArcSharedString()));
-        shared_strings_serializer_.read_shared_strings(shared_strings_xml, shared_strings);
+		xlnt::shared_strings_serializer::read_shared_strings(shared_strings_xml, shared_strings);
 
         for (auto shared_string : shared_strings)
         {
@@ -194,10 +193,8 @@ excel_serializer::excel_serializer(workbook &wb) : workbook_(wb)
 
 void excel_serializer::write_data(bool /*as_template*/)
 {
-    relationship_serializer relationship_serializer_;
-
-    relationship_serializer_.write_relationships(workbook_.get_root_relationships(), "", archive_);
-    relationship_serializer_.write_relationships(workbook_.get_relationships(), constants::ArcWorkbook(), archive_);
+    relationship_serializer::write_relationships(workbook_.get_root_relationships(), "", archive_);
+    relationship_serializer::write_relationships(workbook_.get_relationships(), constants::ArcWorkbook(), archive_);
 
     xml_document properties_app_xml;
     workbook_serializer workbook_serializer_(workbook_);
@@ -207,10 +204,9 @@ void excel_serializer::write_data(bool /*as_template*/)
     theme_serializer theme_serializer_;
     archive_.writestr(constants::ArcTheme(), theme_serializer_.write_theme(workbook_.get_loaded_theme()).to_string());
 
-    xlnt::shared_strings_serializer shared_strings_serializer_;
     archive_.writestr(
         constants::ArcSharedString(),
-        xml_serializer::serialize(shared_strings_serializer_.write_shared_strings(workbook_.get_shared_strings())));
+        xml_serializer::serialize(xlnt::shared_strings_serializer::write_shared_strings(workbook_.get_shared_strings())));
 
     archive_.writestr(constants::ArcWorkbook(), xml_serializer::serialize(workbook_serializer_.write_workbook()));
 
diff --git a/source/workbook/workbook.cpp b/source/workbook/workbook.cpp
index b39c2093..2c2db2ae 100644
--- a/source/workbook/workbook.cpp
+++ b/source/workbook/workbook.cpp
@@ -626,6 +626,30 @@ std::size_t workbook::add_style(const xlnt::style &style_)
     return d_->styles_.back().id_;
 }
 
+color workbook::add_indexed_color(const color &rgb_color)
+{
+	std::size_t index = 0;
+
+	for (auto &c : d_->colors_)
+	{
+		if (c.get_rgb_string() == rgb_color.get_rgb_string())
+		{
+			return color(color::type::indexed, index);
+		}
+
+		index++;
+	}
+
+	d_->colors_.push_back(rgb_color);
+
+	return color(color::type::indexed, index);
+}
+
+color workbook::get_indexed_color(const color &indexed_color) const
+{
+	return d_->colors_.at(indexed_color.get_index());
+}
+
 const number_format &workbook::get_number_format(std::size_t style_id) const
 {
     auto number_format_id = d_->styles_[style_id].number_format_id_;
@@ -820,27 +844,27 @@ std::size_t workbook::set_number_format(const xlnt::number_format &format, std::
     return new_style.id_;
 }
 
-std::vector<style> workbook::get_styles() const
+const std::vector<style> &workbook::get_styles() const
 {
     return d_->styles_;
 }
 
-std::vector<number_format> workbook::get_number_formats() const
+const std::vector<number_format> &workbook::get_number_formats() const
 {
     return d_->number_formats_;
 }
 
-std::vector<font> workbook::get_fonts() const
+const std::vector<font> &workbook::get_fonts() const
 {
     return d_->fonts_;
 }
 
-std::vector<border> workbook::get_borders() const
+const std::vector<border> &workbook::get_borders() const
 {
     return d_->borders_;
 }
 
-std::vector<fill> workbook::get_fills() const
+const std::vector<fill> &workbook::get_fills() const
 {
     return d_->fills_;
 }
@@ -850,12 +874,7 @@ void workbook::add_color(const color &rgb)
     d_->colors_.push_back(rgb);
 }
 
-std::string workbook::get_indexed_color(std::size_t color_index) const
-{
-    return d_->colors_.at(color_index).get_rgb_string();
-}
-
-std::vector<color> workbook::get_colors() const
+const std::vector<color> &workbook::get_colors() const
 {
     return d_->colors_;
 }