I use Tamiya fine primer in white or gray and it adhere great. One you have that on the model you can use a hole range of paints.
Below is a model jet engine I printed /made (not printed on the Zortrax) which is painted with Rustoleum all purpose indoor/outdoor paint and Rustoleum Metallic.
https://www.dropbox.com/s/mxbmfp8ff89bx3i/Photo%20Feb%2011%2C%208%2031%2033%20AM.jpg
https://www.dropbox.com/s/da9mx6m3nrjyxrx/Photo%20Feb%2011%2C%208%2032%2020%20AM.jpg
David