I'm using ROS Kinetic with Ubuntu Xenial 16.04

So i've set up my RGB Leds and have it working for turning on or off depending on what is being published. Now I would like to have the Led flashing at a certain frequency, but when I add a while loop to do so, my rosserial python node goes out of sync. How can I do this then?

I have my arduino code, and a custom library for the LEDS (leds.cpp and leds.h) files. There are other operations running such as the motors, i don't know if that affects anything or not. (If not, please ignore them)

Leds.h file:

#ifndef Leds_h
#define Leds_h
#include <Arduino.h>

void initializeLeds();
void setColor(int r, int g, int b);
void flashColor(String name);

#endif

Leds.cpp file:

#include <Leds.h>
#include <Arduino.h>
#include <std_msgs/String.h>
#include "ros.h"


#define R_PIN 44
#define G_PIN 46
#define B_PIN 45

bool initialized = false;

void initializeLeds(){
    pinMode(R_PIN, OUTPUT);
    pinMode(G_PIN, OUTPUT);
    pinMode(B_PIN, OUTPUT);
    initialized = true;
}

void flashColor(String name) {
    while (name=="PreQualify") {
    setColor(0,0,1);
    }

    if (name=="GateAndSurface") {
    setColor(0,1,0);
    }

    if (name=="None") {
    setColor(0,0,0);
    }
}
void setColor(int r, int g, int b){

    if(initialized){
    switch(r) {
    case 0: digitalWrite(R_PIN, LOW);
    break;
    case 1: digitalWrite(R_PIN, HIGH);
    break;
    default:
    break;
    }
    switch(g) {
    case 0: digitalWrite(G_PIN, LOW);
    break;
    case 1: digitalWrite(G_PIN, HIGH);
    break;
    default:
    break;
    }
    switch(b) {
    case 0: digitalWrite(B_PIN, LOW);
    break;
    case 1: digitalWrite(B_PIN, HIGH);
    break;
    default:
    break;
    }

  }
}

Arduino code:

#include <Arduino.h>
#include <ros.h>
#include <geometry_msgs/Twist.h>
#include <std_msgs/Int32.h>
#include <std_msgs/Float32.h>
#include <std_msgs/String.h>
#include <controller_pkg/HorizontalMotors.h>
#include <controller_pkg/VerticalMotors.h>
#include <Motors.h>
#include <Wire.h>
#include <blue_robotics.h>
#include <Servo.h>
#include <Leds.h>
#include <string.h>

//std_msgs::String color;
std_msgs::Float32 depth;
MS5837 pressureSensor;
String name;

// Callback function for left motors
void setHorizontalMotors(const controller_pkg::HorizontalMotors&  motorIntensity)
{
   setHorizontalMotorSpeed(motorIntensity.rightMotor, motorIntensity.leftMotor);
}

// Callback function for simultaneous usage of motors
void setVerticalMotors(const controller_pkg::VerticalMotors& motorIntensity)
{
    setVerticalMotorSpeed(motorIntensity.frontRight, motorIntensity.frontLeft, motorIntensity.backRight, motorIntensity.backLeft);
}

// Callback function for LED lights.
void LEDCallback(const std_msgs::String& msg) {
    name = msg.data;
    flashColor(name);
}

ros::NodeHandle nh;

// Creates all the ROS subscriber objects
ros::Subscriber<controller_pkg::VerticalMotors> subVerticalMotors("vertical_motors", setVerticalMotors);
ros::Subscriber<controller_pkg::HorizontalMotors> subHorizontalMotors("horizontal_motors", setHorizontalMotors);
ros::Subscriber<std_msgs::String> subCurrentMission("CurrentMission", &LEDCallback);

// Create the pressure sensor publisher
ros::Publisher pubToPressureSensor("depth_current", &depth);


void setup() {
  // Initializes the node and prepares for publishing and subscribing.
  nh.initNode();
  nh.advertise(pubToPressureSensor);
  nh.subscribe(subVerticalMotors);
  nh.subscribe(subCurrentMission);
  nh.subscribe(subHorizontalMotors);


  // Initializes all the motors
  initializeVerticalMotors();
  initializeHorizontalMotors("old");

  //initializes leds
  initializeLeds();

  //Initializes wire (protocol to run)
  Wire.begin();

  // If pressure sensor does not initialize, throw error

  while(!pressureSensor.init())
  {

      nh.logerror("Pressure sensor cannot initialize.");

  }

}

void loop()
{

  pressureSensor.read();

  depth.data = pressureSensor.depth()*(3.3);

  pubToPressureSensor.publish(&depth);

  nh.spinOnce();
}

I'd like to add the loop inside my Leds.cpp file, specifically on my flashColor function, that depending on what the string says, it'll flash a different color, but adding a while loop breaks the rosserial node's sync.