Attaching multiple renderbuffers to FBO

I've successfully attached multiple render buffers and their corresponding textures to a frame buffer object. In my test, I attached a depth buffer and a full color buffer. Then I attached the resulting textures to two squares that I render at the same time as the rest of the scene. I didn't notice any performance impact.

Here's my code, nothing fancy, I haven't wrapped up textures, render buffers and frame buffer objects inside actual C++ objects:

FBO::FBO(int width, int height)
 : _width(width),
   _height(height)
{
  // create a depth texture object                                              
  glGenTextures(1, &_depthTex);  glBindTexture(GL_TEXTURE_2D, _depthTex); 
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
  glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, _width, _height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);

  // create a color texture object                                                
  glGenTextures(1, &_colorTex);
  glBindTexture(GL_TEXTURE_2D, _colorTex); 
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
  glBindTexture(GL_TEXTURE_2D, 0);

  // create a framebuffer object
  glGenFramebuffersEXT(1, &_fbo);
  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, _fbo);

  // create a renderbuffer object to store depth info                             
  glGenRenderbuffersEXT(1, &_depthBuffer);
  glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, _depthBuffer);
  glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT,  _width, _height);

  // create a renderbuffer object to store color info                             
  glGenRenderbuffersEXT(1, &_colorBuffer);
  glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, _colorBuffer);
  glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, _width, _height);

  glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, 0);

  // attach a texture to FBO depth attachement point                              
  glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, _depthTex, 0);

  // attach a texture to FBO color attachement point                              
  glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, _colorTex, 0);

  glReadBuffer(GL_NONE);

  // check FBO status                                                            
  checkFramebufferStatus();

  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}