Why Lord Hanuman’s body is covered in Sindhoor?

One day Hanuman asks Sita (wife of Rama) about the red mark on her forehead. Seeing his curiosity, she tells him that she applies sindoor or vermilion (red in color) on her forehead to ensure the long life of her husband. Knowing that applying sindoor will ensure the long life of Rama, he immediately took the vermilion powder and applied it all over his body. When Rama and Sita ask him about it, he says that since Sita is a goddess, a small amount of sindoor will work for her, but he, a mere monkey, needs more of it. He knows that Rama is God. He is the supreme being. But out of his pure love and devotion towards him, he applied sindoor on his whole body.