Update py_colorspaces.rst

mask = cv2.inRange(hsv, lower_green, upper_green)
to
mask = cv2.inRange(hsv, lower_blue, upper_blue)

doc/py_tutorials/py_imgproc/py_colorspaces/py_colorspaces.rst

@@ -58,7 +58,7 @@ Below is the code which are commented in detail :
         upper_blue = np.array([130,255,255])
 
         # Threshold the HSV image to get only blue colors
-        mask = cv2.inRange(hsv, lower_green, upper_green)
+        mask = cv2.inRange(hsv, lower_blue, upper_blue)
 
         # Bitwise-AND mask and original image
         res = cv2.bitwise_and(frame,frame, mask= mask)