send Color4 to GL.Uniform4

Program.cs

@@ -323,7 +323,7 @@ public class Game : GameWindow {
   }
 
   void DrawTexture(Texture texture, Box2i box, Color4 color) {
-    GL.Uniform4(shader.GetUniformLocation("color"), color.R, color.G, color.B, color.A);
+    GL.Uniform4(shader.GetUniformLocation("color"), color);
     SetVertices(box.Min.X, box.Min.Y, box.Size.X, box.Size.Y);
     GL.BufferData(BufferTarget.ArrayBuffer, vertices.Length * sizeof(float), vertices, BufferUsageHint.DynamicDraw);
     GL.BindTexture(TextureTarget.Texture2D, texture.Handle);