Star Wars: Legion - Seperatist - AAT Trade Federation Battle Tank

Q: Can it stand by itself?

Yes, it comes with a stand to keep it up off the ground like it is hovering

Q: Is this the color from the battle of Naboo or is this the clone wars colors?

The plastic comes in a uniform grey color and is intended to be painted. It can be painted in either scheme fairly easily, but do not that the tanks in the Clone Wars cartoon/movie are differently shaped than the live action movie so if trying to duplicate the Clone Wars scheme you will start to notice differences in the proportions and shape of things