Dresden Tram T4D Z - M1:87 (H0)

I was delighted to get a copy of this design of a trolley. However, I suspect that the material I ordered to too brittle.
Since its not a whole model of a trolley, I will make its bottom out of wonderfoam. wheels - I will get somewhere else, Pantographs - I will make out of transparency films.

But here comes a question: How to paint?
First of all, what is the name for a material is it made of (the cheapest option) is it polystyrol?
What is the name and a brand of paint which goes with it - as a perfect fit?
colors - I will choose yellow.cream, and red. and maybe some grey.

it is okay, to paint it with CD markers, or watercolor paint?
Do I need some special delicate tools for painting?

I will appreciate your answers

That looks like Strong & Flexible from the list of materials. That one is nylon based, not polystyrene. Some people have used Poska markers, that works but it will keep the surface texture.

The acrylic paints (Vallejo Model Color, Tamiya Acrylics, etc) you can get from scale model shops will work fine. The first thinned coat will soak into the model, but don't be scared by that, it's normal and will seal the material. Next coat of paint, if applied a bit thick with a flat tool (some plastic cut from a blister box for example), can be used to hide the grain of the surface, or you can use some kind of putty (again, look in scale model shops, Vallejo Plastic Putty is a good one for this, works with water instead of nastier solvents). You can sand the material with fine files or sandpaper, specially after the first (or two) coat(s) so you can see what you are doing, working directly over the white material is eye straining.