Finding that someone has a red aura can mean a variety of things. As in all cases aura colors can mean as many different things as there are different people in the world but this is designed as a basic gudeline for you,.
Use your intuition about what else you know about them to make your choices.
Red is the life colour.
If someone has a great deal of red in their aura they can often be quite likely to be quite aggressive. If however you find that the red permeates the entire aura, running across it in lines, the person will tend to have a very a magnetic personality.
It is also the sex colour, and there is usually more of it in the auras of young people. If someone shows a lot of red but seems to be quite balanced then you can surmise that the person is likely to be enterprising and daring and attractive to the opposite sex.
This is the colour permeating through a lot of the auras of film stars. A bright red in the aura then, shows a healthy balance, cloudy colours indicate things like greed and selfishness.