diff --git a/test/ModelExport.cpp b/test/ModelExport.cpp
index 9cb59aca71..09ce7fccd1 100644
--- a/test/ModelExport.cpp
+++ b/test/ModelExport.cpp
@@ -3,6 +3,8 @@
 #include "imodel.h"
 #include "imodelcache.h"
 #include "imap.h"
+#include "ieclass.h"
+#include "ientity.h"
 #include "algorithm/Scene.h"
 #include "scenelib.h"
 #include "os/path.h"
@@ -85,4 +87,182 @@ TEST_F(ModelExportTest, ExportFolderNotExisting)
     EXPECT_TRUE(fs::exists(outputPath)) << "Exporter didn't create the file " << outputPath;
 }
 
+inline bool surfaceHasVertex(const model::IModelSurface& surface, const std::function<bool(const ArbitraryMeshVertex&)>& functor)
+{
+    for (int i = 0; i < surface.getNumVertices(); ++i)
+    {
+        if (functor(surface.getVertex(i)))
+        {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+const std::string CustomMaterialName = "custom_surface_name";
+const Vector3 VertexColour1(0.1, 0.2, 0.3);
+const Vector3 VertexColour2(0.4, 0.5, 0.6);
+const Vector3 VertexColour3(0.7, 0.8, 0.9);
+
+inline void checkVertexColoursOfExportedModel(const model::IModelExporterPtr& exporter, const std::string& outputPath_)
+{
+    fs::path outputPath = outputPath_;
+    outputPath /= "models/";
+    fs::path filename = "dummy.lwo";
+
+    EXPECT_FALSE(fs::exists(outputPath / filename)) << filename << " already exists in " << outputPath.string();
+
+    exporter->exportToPath(outputPath.string(), filename.string());
+
+    EXPECT_TRUE(fs::exists(outputPath / filename)) << filename << " should exists in " << outputPath.string();
+
+    try
+    {
+        // Create a func_static using this new model
+        auto eclass = GlobalEntityClassManager().findClass("func_static");
+        auto entity = GlobalEntityModule().createEntity(eclass);
+
+        scene::addNodeToContainer(entity, GlobalMapModule().getRoot());
+
+        // This should assign the model node to the entity
+        Node_getEntity(entity)->setKeyValue("model", "models/" + filename.string());
+
+        // Locate the IModel node among the entity's children
+        model::ModelNodePtr model;
+        entity->foreachNode([&](const scene::INodePtr& node)
+        {
+            if (Node_isModel(node))
+            {
+                model = Node_getModel(node);
+            }
+            return true;
+        });
+
+        EXPECT_TRUE(model) << "Could not locate the model node of the entity";
+
+        EXPECT_EQ(model->getIModel().getSurfaceCount(), 1);
+
+        const auto& surface = model->getIModel().getSurface(0);
+        EXPECT_EQ(surface.getDefaultMaterial(), CustomMaterialName);
+
+        EXPECT_EQ(surface.getNumVertices(), 3);
+
+        // The three colours we exported need to be present in the mesh
+        EXPECT_TRUE(surfaceHasVertex(surface, [&](const ArbitraryMeshVertex& vertex)
+        {
+            return math::isNear(vertex.colour, VertexColour1, 0.01);
+        }));
+        EXPECT_TRUE(surfaceHasVertex(surface, [&](const ArbitraryMeshVertex& vertex)
+        {
+            return math::isNear(vertex.colour, VertexColour2, 0.01);
+        }));
+        EXPECT_TRUE(surfaceHasVertex(surface, [&](const ArbitraryMeshVertex& vertex)
+        {
+            return math::isNear(vertex.colour, VertexColour3, 0.01);
+        }));
+
+        fs::remove(outputPath / filename);
+    }
+    catch (const std::exception&)
+    {
+        fs::remove(outputPath / filename);
+        throw;
+    }
+}
+
+// #5717: LWO Model exporter didn't write any vertex colours
+TEST_F(ModelExportTest, LwoVertexColoursAddedByPolygon)
+{
+    auto exporter = GlobalModelFormatManager().getExporter("lwo");
+    EXPECT_TRUE(exporter);
+
+    // Create a few vertices with custom colours
+    std::vector<model::ModelPolygon> polys;
+
+    polys.emplace_back(model::ModelPolygon
+    {
+        ArbitraryMeshVertex(Vertex3f(1,0,0), Normal3f(1,0,0), TexCoord2f(1,0), VertexColour1),
+        ArbitraryMeshVertex(Vertex3f(0,1,0), Normal3f(1,0,0), TexCoord2f(0,0), VertexColour2),
+        ArbitraryMeshVertex(Vertex3f(1,1,0), Normal3f(1,0,0), TexCoord2f(1,0), VertexColour3)
+    });
+
+    exporter->addPolygons(CustomMaterialName, polys, Matrix4::getIdentity());
+
+    checkVertexColoursOfExportedModel(exporter, _context.getTestProjectPath());
+}
+
+class TestModelSurface :
+    public model::IIndexedModelSurface
+{
+public:
+    std::vector<ArbitraryMeshVertex> vertices;
+    std::vector<unsigned int> indices;
+
+    int getNumVertices() const override
+    {
+        return static_cast<int>(vertices.size());
+    }
+
+    int getNumTriangles() const override
+    {
+        return static_cast<int>(indices.size() / 3);
+    }
+
+    const ArbitraryMeshVertex& getVertex(int vertexNum) const override
+    {
+        return vertices[vertexNum];
+    }
+    
+    model::ModelPolygon getPolygon(int polygonNum) const override
+    {
+        return model::ModelPolygon
+        {
+            vertices[polygonNum * 3 + 0],
+            vertices[polygonNum * 3 + 1],
+            vertices[polygonNum * 3 + 2]
+        };
+    }
+    
+    const std::string& getDefaultMaterial() const override
+    {
+        return CustomMaterialName;
+    }
+    
+    const std::string& getActiveMaterial() const override
+    {
+        return getDefaultMaterial();
+    }
+    
+    const std::vector<ArbitraryMeshVertex>& getVertexArray() const override
+    {
+        return vertices;
+    }
+    
+    const std::vector<unsigned int>& getIndexArray() const override
+    {
+        return indices;
+    }
+};
+
+TEST_F(ModelExportTest, LwoVertexColoursAddedBySurface)
+{
+    auto exporter = GlobalModelFormatManager().getExporter("lwo");
+    EXPECT_TRUE(exporter);
+
+    // Create a few vertices with custom colours
+    TestModelSurface surface;
+
+    surface.vertices.emplace_back(Vertex3f(1, 0, 0), Normal3f(1, 0, 0), TexCoord2f(1, 0), VertexColour1);
+    surface.vertices.emplace_back(Vertex3f(0, 1, 0), Normal3f(1, 0, 0), TexCoord2f(0, 0), VertexColour2);
+    surface.vertices.emplace_back(Vertex3f(1, 1, 0), Normal3f(1, 0, 0), TexCoord2f(1, 0), VertexColour3);
+    surface.indices.push_back(0);
+    surface.indices.push_back(1);
+    surface.indices.push_back(2);
+    
+    exporter->addSurface(surface, Matrix4::getIdentity());
+
+    checkVertexColoursOfExportedModel(exporter, _context.getTestProjectPath());
+}
+
 }