Every night, before going to bed, think about your day and give it a color. Don't give it too much thought, just choose a color. As time goes (1-2 Months), you may find that you've used all the colors or some of the colors. you need to check if any colors are missing or not used enough, because every color of the rainbow has a certain effect on you. Missing colors:
If red is missing, you are exhausted or overtired, get some sleep or have some exercise to raise your energy level.
if orange is missing, your confidence and self-esteem are likely to be low or missing. dancing is a good exercise here.
If yellow is missing, you are likely to be nervous or suffering from stress. massage the area just above your navel.
If green is missing, you may have relationship problems. Have a walk in the park, walk barefoot on the grass and enjoy the healing that comes from the greens you see.
If blue is missing, you are likely to feel unsupported or let down by someone close to you. walk near the water, sit beside a fountain or take a walk along the beach.
If indigo is missing, you are being taken advantage of or not fully appreciated by people close to you. take some time out by yourself.
if purple is missing, you have temporarily lost contact with your spiritual self. spend sometime alone in a place that is spiritual to you.
*Note to self: What about colorless days*
Source: Color Magic for Beginners By Richard Webster.