(N.B. all of the following is based upon my personal experience, and the consequent verifications of my equally strange new-age inclined friends. I have not yet seen much of what i have written here in published form as 'traditionally' accepted technique or theory. Doesn't mean it's not there i just haven't seen it. But do not take this node as canon but just as my opinion/experience)
Color theory is a quirky little thing that kind of combines the ideas of aura reading and spirit or essence. Auras are energy fields that surround the body--and *fluctuate* according to the mood and mindset of the person. *COLORS* however are static. The "color" a person is indicative of the nature of their essence/spirit/soul. Traditional color definitions apply somewhat here--purple people tend to be intuitive and introspective, blue-green people have healing and or nurturing natures--but this is *not* a hard-and-fast fact. (Quite possibly due to the fact that "traditional" definitions have become jumbled over the years). Shade, intensity, and clarity fluctuate according to mood but a red person will always be some derivative of red in essence whine in aura they could be blue with a yellow stripe across a chakra at one moment and silverish the next, if a sudden mood change occurred.
There are some interesting side effects to knowing color theory. Nine times out of ten, when I ask a person what one color of clothing they do not or feel like they can not wear, the color they give in response will actually *be* their soul color. My speculation on this is that people are innately--and usually subconsciously--reluctant to reveal something so personal as the nature of their soul to complete strangers, so they intuitively steer away from their soul color. Additionally, in the case of my female friends (i don't tend to ask guys this question, or be in a place to know) who have repainted or wallpapered their bedrooms and have chosen the color themselves, the dominant color of the room *is* the soul color. This is, perhaps, because most people consider their bedroom their own true space, their innermost sanctuary and so want it to reflect their essence. Third weird observation: the concept of the color wheel too many of us learned in grade school art, and all that jazz about complimentary colors--it seems very much to be true. Opposites attract, colorwise. I am yellow/gold. All my closest friends, the ones i'd trust with my very life are purple. Usually deep purple. My soulmate is deep purple. When i look at most of my friends and their relationships and friendships i notice this pattern in them as well--the people they are closest to are either (less commonly but still frequent) their own color or their complimentary color, the one opposite theirs on the color wheel].
Enough of that. If you are still reading thus far you probably want to know how to see colors, on yourself or other people. Unfortunately there is no sure-fire way. You have to find your own technique. For me and most people i've taught to see colors, it is *not* a seeing but sensing. I close my eyes and concentrate on the person and end up half 'seeing' half sensing the color inside my head kind of across the inside of my eyeballs. One of my friends squints until her eyes are almost entirely closed and then actually sees the color across the bottom of her eyelid. Really the most important thing is just to concentrate and focus on the target. Start with people you are close to, that you already have close bonds with. Try to sense it, then ask (or find out somehow) their no-wear clothes color and the color of their bedroom. Those are both by *no* means *rules* but often good indications. Once you do manage to sense the color you will *know* it immediately, you will *feel* it and know it could not possibly be anything else. If you know their animal totem the color might be derivative from that, or a color traditionally associated with that animal. It is something that really cannot be explained or rationalized just felt and known. One helpful thing in learning it is to get a friend who is also interested and go out somewhere, pick random people, try to 'color' them, independently, write down the color you think is right, and compare notes after you have *both* written--sometimes the power of suggestion will change the second person's mind. When you start matching most times, that is a good indicator your technique and sensitivity are growing stronger and more personally correct. Good luck!