Colour means different things to different people, it is associated with mood, memory, time of year, occasion, well-being, emotion, atmosphere and of course the chakra system.
You can ask a person what the colour yellow means to them and they might say, the sun or summer but another person might say cowardice and yet another might say illness, sickness.
You can see how the experiences and memories of a person can affect the way they see the world and the colour within it. It's also worth remembering that some people are colourblind and see shades and tones rather than blocks of differing colours so the world looks very different to them. They will of course be able to see colour in the spirit world whilst their consciousness is in that place but for some reason they are denied it in the physical world of earth.
For you to connect to colour and its symbolism by yourself or in a group here is a simple exercise for you to try. . .
Collect some objects of different plain colours or you could make a bunch of ribbons or use your imagination if it's strong enough to hold the image for long enough for you to read it. You could use candles, flowers, paints, beads, anything that is easy for you to gather.
Next when it is quiet and you won't be disturbed, sit and breathe until you feel peaceful. There is no special technique for this but if your mind is particularly busy try to imagine a waterfall or a gentle stream where the intruding thoughts can flow away from you leaving your mind free to do other things for a while.
When you are ready select a colour to work with, study the colour and the tone or shade you have chosen. Then allow the meaning of the colour to come to you. For example let's look at blue. The tone of blue is rich, royal blue. What does that mean to you? How does the colour make you feel? Calm perhaps, safe or a memory surfaces that has feelings attached to it that you can relate to royal blue?
Does it remind you of deep water and if so what emotions do you feel? Perhaps it reminds you of someone's eyes from the past. Focus on the emotions attached to that memory. Is blue always male, naval or conformation?
Spiritually speaking such a blue is often connected to the power of healing and spiritual presence but you may have a different view. It's worth researching the standard meanings of colours and what they are associated with but ultimately your own inner connection with a colour is what will give you the information you can work with further when and if you want to read a person's aura, the choice of clothing colour, the vibration of a room's decor and so on.
Colour surrounds us both in our energy field and our earthly world and can tell us a lot about a person and their mood or state of mind. Because colour surrounds us it is easy to practise the meanings of it. Wherever you are you can question how a colour makes you feel, what it stands for in your life and how you react to its intensity.
For instance every colour has many grades of intensity so if we take the colour pink as an example we can see that a pale, delicate shade of pink could perhaps relate to a baby girl, gentle feminine energy, softness and kindness. Go to a much darker shade such as cerise and we feel a deeper kind of love, perhaps the love of a mother, it's still a feminine energy but stronger and holding more passion. To take the shade further and move to red it is easy to relate this to love, deep and real. It could also mean the life force, blood in the veins, the heart and circulatory system, anger, or a fiery temper but this comes down to your own experience and gut feeling when reading the colour particularly if it is in direct connection with a person.
Every individual is unique and so is their aura because it changes from moment to moment depending upon their thoughts and ideas. Practise using colour in your life by wearing colour, having colour around you and even thinking about colour and its traditional meaning opposed to how it makes you feel and how you interpret it.
A medium will use the skill of colour reading along with the other senses that the medium employs to gain information about a client or situation but will also use colour in visualisation when giving healing. During healing colour relates directly to the chakras of the energy body and sometimes restoring colour to the system is all that's needed to help a person back to well-being.
Why not experiment with colour by visualising different colours, one at a time, in your own energy field to see how they affect you?