diff --git a/example.cpp b/example.cpp
index 2841dbb..d7e6bd3 100644
--- a/example.cpp
+++ b/example.cpp
@@ -27,7 +27,7 @@ int main(int argc, char *argv[])
         return 1;
     }
 
-    Identiconpp identicon(5, 5, "ffffffff", {"000000ff", "000000"});
+    Identiconpp identicon(5, 5, 0xffffffff, { 0x000000ff, 0x000000 });
 
     return 0;
 }
diff --git a/src/identiconpp.cpp b/src/identiconpp.cpp
index 6f048d0..fcaf2de 100644
--- a/src/identiconpp.cpp
+++ b/src/identiconpp.cpp
@@ -20,26 +20,12 @@
 #include "debug.hpp"
 
 Identiconpp::Identiconpp(const uint8_t rows, const uint8_t columns,
-                         const string &background,
-                         const vector<string> &foreground)
+                         const uint32_t background,
+                         const vector<uint32_t> &foreground)
 : _rows(rows)
 , _columns(columns)
 , _background(background)
 , _foreground(foreground)
 {
-    // TODO: Check rows and columns
-    if (_background.size() != 8)
-    {
-        throw std::invalid_argument("Background color has the wrong format: " +
-                                    _background);
-    }
-    for (const string &color : _foreground)
-    {
-        if (color.size() != 8)
-        {
-            throw std::invalid_argument("Foreground color has the wrong format: " +
-                                        color);
-        }
-    }
 }
 
diff --git a/src/identiconpp.hpp b/src/identiconpp.hpp
index 43ab1a0..9e90fa6 100644
--- a/src/identiconpp.hpp
+++ b/src/identiconpp.hpp
@@ -19,6 +19,7 @@
 #include <vector>
 
 using std::uint8_t;
+using std::uint32_t;
 using std::string;
 using std::vector;
 
@@ -43,12 +44,12 @@ public:
      *  @param  foreground  vector of foreground colors
      */
     explicit Identiconpp(const uint8_t rows, const uint8_t columns,
-                         const string &background = "ffffffff",
-                         const vector<string> &foreground = { "000000ff" } );
+                         const uint32_t background = 0xffffffff,
+                         const vector<uint32_t> &foreground = { 0x000000ff } );
 
 private:
     const uint8_t _rows;
     const uint8_t _columns;
-    const string _background;
-    const vector<string> _foreground;
+    const uint32_t _background;
+    const vector<uint32_t> _foreground;
 };