Hi Tina,
I'm sorry to hear that you have lost your father.
It is my understanding that spirits are neither black, white, nor purple. What we perceive as color has to be processed in our brain and the brain can only determine the amount of light the object reflects - which will be seen by us as different colors in the spectrum. But your father is neither white nor black while he is a spirit.
Is it possible that your mind wanted it to be your father? Would you have seen your father's features because you wanted to? Is it possible that you may have some unresolved issues? It is common to 'see' the spirit of a person we loved after they have passed.
The Christian bible says that "...the dead know nothing of the living..." so if you are a Christian, the issue should be resolved.
If you are not a Christian, then perhaps a spirit did appear to you. That does not mean that it was your father.
I feel that you should be very careful because you have no protection against these spirits unless you can call on the name of Jesus.
You can believe whatever you choose, but you should be very careful before you decide to attempt to pursue a 'conversation' with this spirit. Possession is more common than many people realize.
But there is a way you can test this spirit should it return. Spirits want only 3 things from you and in this exact order.
1. They want to engage you. Either in conversation or they will make you accept their presence as natural.
2. They want to obsesse you. In that they want your every waking minute to be consumed with them or thoughts of them.
3. Eventually they will want to possess you. At this stage you have already invited them in so they get to decide if or when they ever leave your body and generally they will stay until the day you die unless you have it exorcised.
If this spirit is your father and it returns then perhaps he has just come to put your mind to rest about something.
If this spirit is not your father and he returns again, he is trying to get you accustomed to seeing him so that you accept his presence as normal.
It is my understanding that your only recourse then will be to call on the name of Jesus. But you must believe.
Please remember that this is just my opinion. I do not know if I have more of a revelation about spirits than anyone else in the world...but I do know what they are and how to deal with them.
Be careful and God bless.