1. INTRODUCTION  
1.1. Two-phase Formation Scenario for Massive Galaxies  
1.2. Color Gradients of Massive Elliptical Galaxies  
1.3. The Red Sequence and the \( M_{*} \) -color Relation  

2. PHOTOMETRIC DATA OF NEARBY MASSIVE ELLIPTICALS  

3. MULTI-COMPONENT DECOMPOSITION IN B AND R BANDS  

4. RESULTS  
4.1. Color Difference between Inner and Outer Components  
4.2. Average Merger Mass Ratio  

5. DISCUSSION  
5.1. Color Gradients for the In-situ and Accreted Components  
5.2. Uncertainty of the Slope of Mass-Color Relation  
5.3. Details about the Minor Mergers  
5.4. Future Directions and Applications  

6. SUMMARY