Isn't a pinkish aura meant to be quite rare and show someone who likes to defy convention? (so new to auras I still don't know if I can actually believe them yet).
I guess people's perceptions would affect how you see a person's aura. This takes the old saying 'rose-coloured glasses' wayyy out of it's original context. The 3rd eye chakra, that is said to process aura sight, sits between the throat chakra (centre of expression) and crown chakra centre (higher knowledge, wisdom). I guess, how a person see auras, develops from being mostly influenced by the throat chakra (our energy filtered into the outside world), therefore at first how we percieve other's energy directly links to how we filter our own external energy. Slowly, as we begin to gain understanding and clarity of this ability, it 'ascends' and becomes more influenced by the crown chakra and your perception of other people's auras becomes more based on the truth inherent in the aura and through an understanding of their entire person not just the manifestation of their external energy.
I could be very wrong though.
From an astrological perspective, external energy (what makes a person's aura what it is) could very likely relate to the placement of mars in their natal chart. Mars rules how we express our inner energy in the outside world. This isn't proven yet though but if you'd like to post/pm your birth details, I'd really like to see if I can guess the colours of your aura based on the chart.