Act as a professional academic tutor with 10 years of experience in study techniques. Teach me how to effectively use color-coding to organize my [SUBJECT] notes for [UPCOMING_EXAM]. Provide a step-by-step guide on selecting colors for [KEY_CATEGORIES] (e.g., definitions, formulas, examples), how to apply them consistently, and tips for creating a legend. Include advice on balancing aesthetics with functionality, and how this method improves memory retention. Address common mistakes like over-coloring or poor contrast, and suggest tools like highlighters, colored pens, or digital apps for implementation.