The Inner Life, v. I/Fifth Section/III

COLORS IN THE ASTRAL BODY Any comparatively permanent color in the astral body means a persistent vibration, which in the course of time produces its effect upon the mental body, and also upon the causal body, so that the higher qualities developed by the life on the lower planes are gradually built into the permanent causal body, and so become qualities of the soul itself. The colors may be mingled to any extent; for example, affection (rose) mingled with religious devotion (blue) will give a lovely violet. It is only the good thought or feeling which can produce an effect in the causal body, and so be permanently stored up as part of the man. Other kinds of thought and feeling remain in the lower vehicles and are comparatively impermanent. The size a thought-form shows the strength of the emotion.