I'm new to openCV, trying to use it differentiate objects based on its clolor. Checked some the available codes but getting error. Uisng Raspberry Pi camera for taking image.

I'm using Raspberry Pi and OpenCV-3.0.0. trying to make a project which can able to sort objects based on its color, for eg; it select red objects and rejects green or yellow objects. I'm done with the mechanism, but when I tried the existing codes in Internet for sorting, I am getting error. Can someone help me with the code. Thanks