Yes, I think that would be the issue. I'm glad you were able to get everything working.
This wouldn't be in the Arduino sketch - it is in the Python software that run on the host computer. In particular see the constants.py file in "python/Colorimeter/colorimeter/" sub-directory in the repository https://bitbucket.org/iorodeo/colorimeter/src
The default ports are set on lines 8-10 of constants.py as shown below.
You should be able to change it to whatever you like.