What about the Mysterions

Hint 1 of 5:

Appearance : multicolored balls.

Hint 2 of 5:

Ship style : huge ball in a net sphere.

Hint 3 of 5:

Home world : none known.

Hint 4 of 5:

Use posture: friendly.

Hint 5 of 5:

Note: They are not good listeners or talkers.  No armament, harmless.