People mention the color of candles a lot in spell work. I felt the urge to write about many of the ways colors effect our lives. This should be taken into consideration when doing any working.
First of all, think of how each color makes you feel. While it is true that every color has different "properties", they also have a different effect on each one of us due to our experiences. Take time to see how each color effects you as a person. Sense the vibrations or "energy" each give off.
Next, take a look at your surroundings, and see how it makes you feel. Write down how each room you are in feels, and the main colors in it. Most people do not think about it, but the colors you pick for your walls and carpeting effect how you feel. Dingy colors tend to sedate or depress, bright tend to make you more awake and energetic, pastels often relax. Even the tone effects you.
Even the colors of the foods we eat effect us (natural foods). Red is said to help with your heart. Green foods help to heal. Purple/blue foods help with protection and psychic awareness. Yellow help to increase joy etc.
Now take a look at your wardrobe. Most of us have favorite outfits. Look at the colors in those. Once again, how do they make you feel. You might wear black or darker cloths because it helps you to cope, make your mood neutral or look slimming. You might wear bright colors because they make you feel cheerful or vibrant. Whatever the reason, we are drawn to certain colors by how they effect us.
Take a good look at everything around you and really sense how it makes you feel. This will show you that color can effect you in many ways. As for magic, it is good to know how a room makes you feel, and how to change that. Any seasoned practitioner knows you would not want to work on positivity in a room that surrounds you with bad feelings.