I do sometimes see them, and other times I don't and when I do see, then I can't distinguish the colour!
But you are SO right about FEELING the aura especially depending on the mood of the person. I once was staying in a cute garden cottage of a friend, who had her own business running from home and the "lounge" was converted into office space. One day I walked in and only the one girl was still working so I struck up a conversation... but as I got WITHIN 3 - 4 METERS of her, the air around me got thick and mucky and bleg... I wrote it off to the fact that it was hot and there were barely any windows open. However, within 1 minute of our conversation she revealed to me that she had had the sh1*-iest day IMAGINABLE! Immediately I realised that that was it! I felt her aura.
Funny thing, thoug: this woman and I are still in contact and she is also pagan (she promised that once her line at home is sorted, she'll come join the chat here cuz the site's blocked at worked for her)... but there is the strangest "bond" between us. We hardly ever see each other, but when we do we get on like KIDS! She's such a joy and the connection between her life and my life's events are often SO similar it is uncanny! But I'm not going to go into her story in too much detail because its a very long and intricate one, but VERY interesting.