Hanuman Jayanti is celebrated to commemorate the birth of Hanuman, the Vanara god, widely venerated throughout India.
Hanuman is an ardent devotee of Lord Rama, and is worshipped for his unflinching devotion to the god. From early morning, devotees flock Hanuman temples to worship him.
Hanuman Jayanti is an important festival of Hindus. Hanuman is the symbol of strength and energy. Hanuman is said to be able to assume any form at will, wield rocks, move mountains, dart through the air, seize the clouds and rival Garuda in swiftness of flight. He is worshipped in folk tradition as a deity with magical powers and the ability to conquer evil spirits. The devotees visit temples and apply tilaka of shendur to their foreheads from Hanuman’s idol as Hanuman himself was of that color.
A few thousand years before Ramayan time (in the latter part of Tretayuga 2 million years ago), several divine souls came to Earth and modified the bodies of ape like creatures through evolutionary methods (genetic mutation) so that the animals could play the role of vehicles for these divine souls. That’s how Vanara race with reddish orange color (hues of deep orange and light red) was established before the Ramayan time. Hanuman was born into this Vanara community and was in reddish orange color. So in all the Hanuman temples we see Hanuman colored in different hues of reddish orange color.