diff --git a/config/base/base.mk b/config/base/base.mk
index e7a2ef3..d746a7d 100644
--- a/config/base/base.mk
+++ b/config/base/base.mk
@@ -4,7 +4,7 @@ this_cxxflags += -Werror # treat warnings as errors
 this_cxxflags += -Wfatal-errors # stop on first error encountered
 this_cxxflags += -fstrict-aliasing # in order to comply with the c++ standard more strictly
 this_cxxflags += -g # include debugging symbols
-this_cxxflags += -std=c++17
+this_cxxflags += -std=c++20
 this_cxxflags += -fPIC
 this_cxxflags += -Wno-deprecated-declarations
 
diff --git a/src/bedsidemon/spo2/spo2_parameter_window.cpp b/src/bedsidemon/spo2/spo2_parameter_window.cpp
index 35d907b..7591d68 100644
--- a/src/bedsidemon/spo2/spo2_parameter_window.cpp
+++ b/src/bedsidemon/spo2/spo2_parameter_window.cpp
@@ -337,7 +337,8 @@ void spo2_parameter_window::on_heart_timer_expired()
 	// std::cout << "heart" << std::endl;
 }
 
-void spo2_parameter_window::on_color_change(){
-    this->spo2_value.set_color(this->get_color());
-    this->waveform.set_color(this->get_color());
+void spo2_parameter_window::on_color_change()
+{
+	this->spo2_value.set_color(this->get_color());
+	this->waveform.set_color(this->get_color());
 }
diff --git a/src/bedsidemon/spo2/spo2_parameter_window.hpp b/src/bedsidemon/spo2/spo2_parameter_window.hpp
index 880ce56..7a4b593 100644
--- a/src/bedsidemon/spo2/spo2_parameter_window.hpp
+++ b/src/bedsidemon/spo2/spo2_parameter_window.hpp
@@ -68,7 +68,7 @@ class spo2_parameter_window :
 
 	void set(const spo2_measurement& meas);
 
-	void on_color_change()override;
+	void on_color_change() override;
 
 	// clang-format off
 	constexpr static const std::array<uint32_t, 4> possible_colors = {{
diff --git a/src/bedsidemon/spo2/spo2_parameter_window_menu.cpp b/src/bedsidemon/spo2/spo2_parameter_window_menu.cpp
index 567b2c8..5993e03 100644
--- a/src/bedsidemon/spo2/spo2_parameter_window_menu.cpp
+++ b/src/bedsidemon/spo2/spo2_parameter_window_menu.cpp
@@ -21,6 +21,8 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 #include "spo2_parameter_window_menu.hpp"
 
+#include <algorithm>
+
 #include <ruis/widget/button/selection_box.hpp>
 #include <ruis/widget/label/gap.hpp>
 #include <ruis/widget/label/margins.hpp>
@@ -31,6 +33,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include "spo2_parameter_window.hpp"
 
 using namespace std::string_literals;
+using namespace std::string_view_literals;
 
 using namespace ruis::length_literals;
 
@@ -146,7 +149,25 @@ spo2_parameter_window_menu::spo2_parameter_window_menu(
     ),
     spo2_pw(std::move(spo2_pw))
 // clang-format on
-{}
+{
+	{
+		auto& sb = this->get_widget_as<ruis::selection_box>("color_selection_box"sv);
+
+		if (auto pw = this->spo2_pw.lock()) {
+			const auto& colors = spo2_parameter_window::possible_colors;
+			auto i = std::ranges::find(colors, pw->get_color());
+			sb.set_selection(std::distance(colors.begin(), i));
+		}
+
+		sb.selection_handler = [this](ruis::selection_box& sb) {
+			auto pw = this->spo2_pw.lock();
+			if (!pw) {
+				return;
+			}
+			pw->set_color(spo2_parameter_window::possible_colors.at(sb.get_selection()));
+		};
+	}
+}
 
 void spo2_parameter_window_menu::on_close()
 {