White: heavenly energy, offering protection
Blue: symbol of truth, offering calming energy
Green: symbol of love, offering healing energy
Red: symbol of strength, offering courage
Orange: symbol of the future, offering guidance
Purple: symbol of knowledge, offering information; may be willing to communicate with you
Lavender: symbol of youth, offering creativity
Yellow: symbol of happiness, offering joyful energy
Black: grief and trauma; if seen, leave the area immediately
Gray or Brown: fear and panic; if seen, leave the area imemediately
It is possible, but very difficult to directly communicate with orbs. Most orbs will run off or disappear upon being approached, if you can even see them in the first place. If you are to communicate with an orb, be prepared to ask only important questions, and be willing to bare your heart and mind open for them to see. In my experience, informant (purple) orbs are the most willing to communicate. You do not need a ouija board or anything of the sort. You only need patience and an infinite amount of respect for the orb you speak to. Do not go seeking for an orb for the sole purpose of communicating with it. Let it come to you. Then, you simply ask "May I speak with you?" The orb will drift towards or away from you, or it may disappear entirely. If it does not move towards you, do not press further. Let it go. Be aware that orbs do not communicate in words, only in feelings via energy, but you will still be able to understand any information it gives you.
It is very easy to mistake a dust particle for a spirit orb in a picture, but it is easy to identify them with practice. Spirit orbs are more opaque than dust, and they do not often appear with many others around them. Dust can form in all sorts of shapes, cluster with however much dust it wants to, and it is very easy to see through. Here is a visual comparison for reference (from CallSIGHT):