First cut of pulling out the relevant parts of my original game to make a little framework.

tests/palette.cpp

@@ -0,0 +1,24 @@
+#include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
+#include <string>
+#include "graphics/palette.hpp"
+
+using namespace fmt;
+
+TEST_CASE("color palette test", "[color-palette]") {
+  palette::init();
+  REQUIRE(palette::initialized() == true);
+  // confirm it's idempotent
+  palette::init();
+
+  sf::Color expect{10, 10, 10, 255};
+
+  auto gui_text = palette::get("gui/theme:dark_dark");
+  REQUIRE(gui_text == expect);
+
+  gui_text = palette::get("gui/theme", "mid");
+  REQUIRE(gui_text != expect);
+
+  expect = {100, 100, 100, 255};
+  REQUIRE(gui_text == expect);
+}