Well i learned that my aura is almost pure black with grayish tinge to it. I have heard black and grey is very bad for the aura and i want to clarify this.
Usually you can't be pure black. If someone has a black aura then it should only have a black tinge to it. I have no idea why your aura would be totally black, as I have never heard of that happening. Usually black or grey means stress or somethings going wrong in your life. I hope things aren't that bad, and the person only saw your aura wrong.
Blessed be!
Are you a pessamist? Depressed? Upset about something? Stressed out? My energy will turn dark black or dark red when I am very angry or upset. I can see this, and so can others who are clairvoyant. But it is blue the rest of the time. Auras change with emotions and mentality. They are a mirror that reflect what is inside. I don't believe you need to cleanse your aura. I believe you need to look inside of yourself and your personal negativity.
You can clease yourself to remove the negativity that has built up, and you should do this everyday. I do when I shower. But you need to assess the source, which is you. If you want a change, then you need to work on that change by finding peace in yourself and a positive attitude. Meditating everyday can help too. I like to practice yoga when I am stressed as well.
If it were "injury" to your aura, you would have dark spots/areas, not a fully black aura.
Once again, WhiteRav3n is quite right. Auras are a reflexion of what is inside and you need to look into yourself to gain some clarity on the situation, find peace, and possibly cleanse yourself to remove negative energy
However, I don't always see black (or grey) as a negative colour. Firstly, to me, grey symbolizes balance. In the case of black, yes it can signify negativity, lack of forgiveness, pessimism, depression and those things.
Generally, the brighter and clearer the colors in the aura, the more positive and healthy that person is on various levels. Murky, dull colors usually denote lower vibrations, blocks, issues, negativity, etc. This does not mean that black is "bad."
A black aura can represent mystery, change, power,transcendence of ordinary reality, dignity and new potential. Black can also be consciously employed to uncover whatever is hidden, which can be helpful. Also, in fact some people say that a black aura is a sign of people who are great with energy work, however this is based on opinion.
In the end, black can be a colour of both negativity and positivity.
A completely black aura is very rare. Some say it means the persons energy is in perfect balance. Black does not always mean bad, as white is not always good. Dull thin auras are the ones that are concerning. If it is vibrant and extends well beyond the bodies outline, it is not really a bad thing.