Yellows:
are the most fun-loving, free-spirited, energetic, and childlike personalities in the aura spectrum. Yellows are wonderful, sensitive, optimistic beings, whose life purpose is to bring joy to people, to have fun, and to help heal the planet.
Yellows can either be very shy and sensitive, or they can be the life of the party. These playful characters have a great sense of humor. They love to laugh and to make others laugh. Yellows believe life is to be enjoyed. They like to live life freely and spontaneously. With a perpetual smile on their face, they remind people to not take themselves or their problems too seriously.
Yellows would prefer not to work at all, unless their work was fun, playful, or creative. They love nature, and often have concerns for the survival of wildlife and the environment. Dogs are very drawn to Yellows and often become their best friends.
http://www.auracolors.com/about-your-auracolors.html#yellows
The Red being around the head could have been from the type of mood you were in..If Red is around the outer bands of the aura also known as a Red Overlay it is usually added to the outer bands of the aura early on in life because the person felt a need for protection. People may also add a Red Overlay if they have been physically, emotionally or mentally abandoned or rejected.Or have had a life-threatening situation at birth or at a young age, which caused them to perceive that they may die, or that the world was not a safe place.