For the collisions part: Are you actually using particles for the simulation or are you using a fluid sim?

If you are using particles then you need to set the cup as a collision object.

If you are using a fluid physics then the cup needs to be set as an obstacle in the physics/fluid settings. Maybe this video can help: https://www.youtube.com/watch?v=YgwKPP2ZEjI. At about 10 minutes he starts working on the actual fluid sim (before that is just basic lighting setup) and at 17:00 is where he starts setting up the glass that the water will be going into.

For the color part: I don't know about coloring particles directly - I have just been using objects as the particle (like in my screenshot above where I used spheres) and every tutorial I have seen using colored particles has also used an object as the particle. Maybe you can color a particle directly without it needing to be an object in Blender Internal, but I am not sure.