diff --git a/test/unit/color/css_color.cpp b/test/unit/color/css_color.cpp
new file mode 100644
index 000000000..38e151890
--- /dev/null
+++ b/test/unit/color/css_color.cpp
@@ -0,0 +1,38 @@
+#include "catch.hpp"
+#include <mapnik/css_color_grammar.hpp>
+#include <mapnik/safe_cast.hpp>
+
+TEST_CASE("css color") {
+
+    SECTION("conversions")
+    {
+        mapnik::percent_conv_impl conv;
+        CHECK( conv(1.0) == 3 );
+        CHECK( conv(60.0) == 153 );
+        // should not overflow on invalid input
+        CHECK( conv(100000.0) == 255 );
+        CHECK( conv(-100000.0) == 0 );
+
+        mapnik::alpha_conv_impl conv2;
+        CHECK( conv2(0.5) == 128 );
+        CHECK( conv2(1.0) == 255 );
+        // should not overflow on invalid input
+        CHECK( conv2(60.0) == 255 );
+        CHECK( conv2(100000.0) == 255 );
+        CHECK( conv2(-100000.0) == 0 );
+
+        mapnik::hsl_conv_impl conv3;
+        mapnik::color c;
+        conv3(c, 1.0, 1.0, 1.0);
+        CHECK( c.alpha() == 255 );
+        CHECK( c.red() == 3 );
+        CHECK( c.green() == 3 );
+        CHECK( c.blue() == 3 );
+        // invalid
+        conv3(c, -1, -1, -1);
+        CHECK( c.alpha() == 255 ); // should not be touched by hsl converter
+        CHECK( c.red() == 0 );
+        CHECK( c.green() == 0 );
+        CHECK( c.blue() == 0 );
+    }
+}
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