Why is the Gopuram in the picture painted white while other Gopurams look Well decorated and painted ?

Why is the Gopuram in the picture (Srirangam Temple Tamilnadu)painted white when other Gopurams look Well decorated?

Here below is the brief explanation about it

  On the eastern entrance of the Srirangam temple, there stands a white tower, popularly known as the Vellayi Gopuram. It is generally believed that the tower is so called since it has been painted white by the temple authorities. But the tower has actually been named after a Devadasi called Vellayi who had sacrificed her life to protect the idol of Namperumal from the Sultanate forces who had invaded the temple.

Srirangam was attacked by the Sultanate forces in the year 1323 during the Tamil month of Vaikasi. Nearly, 12,000 residents of Srirangam island had laid down their lives fighting to protect the temple. The forces attacked the temple and Lord Ranganatha's jewels and the temple gold were taken away.

The forces also wanted to seize the idol of Namperumal, which they believed was made of pure ‘Abaranji' gold. They searched for the idol but the Vaishnavite Acharya, Pillailokacharya had taken the idol away and fled to Madurai. (The idol of Namperumal that left Srirangam in 1323 returned back only in 1371). Unable to locate the idol, the Sultanate forces killed the temple authorities and later launched a massive hunt for Pillailokacharya and Namperumal.

Fearing that the forces would capture the Acharya and the idol, Vellayi, performed a dance before the commander of the forces thus gaining time for Pillailokacharya to escape with the idol.

Her dance lasted for hours together and finally she took the commander to the eastern gopuram and pushed him down. After killing him, Vellayi jumped to her death from the tower chanting the name of Ranganathar.

Hailing Vellayi's sacrifice, the chief of Vijayanagara forces, Kempanna, who drove away the Sultanate forces, named the tower after her. The gopuram continues to be painted white in her memory.

"We honor our Gods for building them crowns called Temples"