     {
       if ( !xOledTaskHandle )
       {
-        return request->send( 501, HTML_HEADER, NOT_PRESENT_ERROR_501 );
-      }
-      response = request->beginResponseStream( HTML_HEADER );
+        return request->send( 501, HEADER_HTML, NOT_PRESENT_ERROR_501 );
+      }
+      response = request->beginResponseStream( HEADER_HTML );
       response->printf( "%i", oledContrast );
       return request->send( response );
     }

      char response[25];

      strftime ( response, sizeof( response ), "%c", localtime ( &systemStart.tv_sec ) );
      return request->send( 200, HTML_HEADER, response );
    }

    else if ( request->hasArg( "channelcolors" ) )
    {
      response = request->beginResponseStream( HTML_HEADER );
      for ( uint8_t channelNumber = 0; channelNumber < NUMBER_OF_CHANNELS; channelNumber++ )
      {
        response->printf( "%s\n", channel[channelNumber].color );

      uint8_t newPWMDepth = request->arg( "pwmdepth" ).toInt();
      if ( newPWMDepth < 11 || newPWMDepth > 16 )
      {
        return request->send( 400, HEADER_HTML, "Invalid PWM depth" );
      }
      if ( ledcNumberOfBits != newPWMDepth )
      {
        setupDimmerPWMfrequency( LEDC_MAXIMUM_FREQ, newPWMDepth );
        preferences.putUInt( "pwmdepth" , ledcNumberOfBits );
      }
      response = request->beginResponseStream( HEADER_HTML );
      response->printf( "%i", ledcNumberOfBits );
      return request->send( response );
    }
