Detecting Red and Blue Squares (beanbags) using Python and CV2

I am new to CV2 and I am looking for some high level guidance for an application. I am working on a program that can detect red and blue beanbags that are in the frame of the camera. I played around with the example code offered by openCV to detect blue colors and modified it slightly to detect red as well.

import cv2
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
cap = cv2.VideoCapture(0)
while(1): # Take each frame _, frame = cap.read() # Convert BGR to HSV hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV) # define range of blue color in HSV lower_blue = np.array([110,50,50]) upper_blue = np.array([130,255,255]) lower_red = np.array([-20, 100, 100]) upper_red = np.array([13, 255, 255]) # Threshold the HSV image to get only blue colors mask = cv2.inRange(hsv, lower_red, upper_red) # Bitwise-AND mask and original image res = cv2.bitwise_and(frame,frame, mask= mask) cv2.imshow('frame',frame) cv2.imshow('mask',mask) cv2.imshow('res',res) k = cv2.waitKey(5) & 0xFF if k == 27: break
cv2.destroyAllWindows()

This is (slightly modified) copied and pasted code from the OpenCV site. I am looking for the correct way to analyze the res numpy array of the dimensions <460, 640, 3> in order to detect that

1. I have red/blue objects(s) on my screen
2. Do something with this information such as print(1 red and 2 blue squares detected)