diff --git a/main/BMP.h b/main/BMP.h
index 4bf9fa4..4926de4 100644
--- a/main/BMP.h
+++ b/main/BMP.h
@@ -42,7 +42,7 @@ public:
     int     getWidth() { return m_info.width; }
     int     getHeight() { return m_info.height; }
 
-private:
+protected:
     FILE *      m_fp;
     header_t    m_header;
     info_t      m_info;
diff --git a/main/Material.cc b/main/Material.cc
index c78bd78..68f90bc 100644
--- a/main/Material.cc
+++ b/main/Material.cc
@@ -1,9 +1,10 @@
 
 #include "Material.h"
 
-const Material Material::white(Color::white);
+const Material Material::white;
 
-Material::Material(const Color & rgb)
+Material::Material()
 {
-    m_rgb = rgb;
+    m_diffuse_color = Color::white;
+    m_specular_color = Color::white;
 }
diff --git a/main/Material.h b/main/Material.h
index 9a97c33..845148f 100644
--- a/main/Material.h
+++ b/main/Material.h
@@ -7,11 +7,14 @@
 class Material
 {
     public:
-        Material(const Color & rgb = Color::white);
+        /* static members */
         static const Material white;
 
+        Material();
+
     protected:
-        Color m_rgb;
+        Color m_diffuse_color;
+        Color m_specular_color;
 };
 
 #endif
diff --git a/main/Scene.h b/main/Scene.h
index 228d7f9..a85fd95 100644
--- a/main/Scene.h
+++ b/main/Scene.h
@@ -32,7 +32,7 @@ class Scene
         ~Scene();
         void render();
 
-    private:
+    protected:
         /* private methods */
         void load(const char * filename);
         void renderPixel(int x, int y, unsigned char * pixel);
diff --git a/shapes/Plane.h b/shapes/Plane.h
index eccff60..dcf799c 100644
--- a/shapes/Plane.h
+++ b/shapes/Plane.h
@@ -11,7 +11,7 @@ class Plane : public Shape
         IntersectList intersect(const Ray & ray);
         Vector getNormalAt(const Vector & pt);
 
-    private:
+    protected:
         double m_a, m_b, m_c, m_d;
 };
 
diff --git a/shapes/Sphere.h b/shapes/Sphere.h
index 02f7111..cbdb132 100644
--- a/shapes/Sphere.h
+++ b/shapes/Sphere.h
@@ -11,7 +11,7 @@ class Sphere : public Shape
         IntersectList intersect(const Ray & ray);
         Vector getNormalAt(const Vector & pt);
 
-    private:
+    protected:
         double m_radius;
         double m_radius2;
 };
diff --git a/util/Ray.h b/util/Ray.h
index 5700090..d251bfe 100644
--- a/util/Ray.h
+++ b/util/Ray.h
@@ -15,7 +15,7 @@ class Ray
         Vector getPositionAt(double dist) const;
         Vector operator[](double dist) const { return getPositionAt(dist); }
 
-    private:
+    protected:
         Vector  m_origin;
         Vector  m_direction;
 };
diff --git a/util/Vector.h b/util/Vector.h
index d290f35..6078ef1 100644
--- a/util/Vector.h
+++ b/util/Vector.h
@@ -17,7 +17,7 @@ class Vector
         Vector proj(const Vector & target) const;
         Vector reflect(const Vector & target) const;
 
-    private:
+    protected:
         double  m_array[3];
 };