Detects Magenta and Green colours using the webcam. Get the colours from here: https://www.ledr.com/colours/multi.htm

OpenCV_Test.py

import cv2
import numpy as np

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 magenta color in HSV
    lower_magenta = np.array([140, 100, 100])
    upper_magenta = np.array([160, 255, 255])

    lower_green = np.array([50, 100, 100])
    upper_green = np.array([70, 255, 255])

    # Threshold the HSV image to get only magenta colors
    mask_magenta = cv2.inRange(hsv, lower_magenta, upper_magenta)
    mask_green = cv2.inRange(hsv, lower_green, upper_green)
    mask = mask_magenta + mask_green

    # Bitwise-AND mask and original image
    res = cv2.bitwise_and(frame, frame, mask=mask)

    cv2.imshow('frame', frame)
    cv2.imshow('mask_magenta', mask_magenta)
    cv2.imshow('mask_green', mask_green)
    cv2.imshow('res', res)
    k = cv2.waitKey(5) & 0xFF
    if k == 27:
        break

cv2.destroyAllWindows()