᯽The hues of Respect᯽

Hanuman covered himself in sindoor to protect Lord Rama hence the name Bajrangi derived.
Many people are aware that Lord Hanuman is also known as Bajrang Bali; in some parts of India, this alias is preferred. However, not everyone is aware of the name's origin.
Lord Hanuman was deeply attached to Lord Rama. Hanuman once asked Sita why she put sindoor on her forehead, She responded that because she is Lord Rama's wife and companion, the sindoor was a symbol of her unconditional love and respect.
Hearing this Hanuman then proceeded to cover his entire body in sindoor as a symbol of his devotion, love, and duty as Lord Rama's protector. Lord Rama was touched by this and granted a boon that those who worshipped Lord Hanuman in the future with sindoor would see all their troubles go away.