Hi MAS3 and everyone else reading this,
first of all thanks for answering so quickly.
My group and I have already found a color sensor , which my professor thinks is appropriate. It's the TSA3200.http://www.elecfreaks.com/store/color-sensor-module-p-285.html?zenid=4lq8mcunanc4t8ecqou87er801
Our professor also recommended a device for communication, which is the Raspberry Pi.He seems to know how it works , so the issues concerning the color sensor and communication seem to be resolved.
The other issues you mentioned are still unresolved though, I will have to talk to my group to discuss how we are going to resolve them.
We have time to finish this project until the end of my semester, which would be the 30th of June.
My group has this course every friday but we see each other almost every day ,except on the weekend, so we have plenty of time to work on the project. We can also ask our professor for help if we are completely stuck on something.
Even so your help is really appreciated, I will talk with my group and probably post our thoughts on monday.