Short answers, pulled from the story.
Akira Kitamura designed the original Mega Man character. Kitamura originally intended the robot to be white before it was repurposed into the blue Mega Man we know today to ensure visibility against the limited color palette of the Nintendo Entertainment System.
The original Mega Man game was released in 1987. This release transformed a humble housekeeping robot named Rockman into a global icon through a stroke of creative desperation.
Mega Man was colored blue to ensure his animations were visible against the limited color palette of the Nintendo Entertainment System. This decision was a technical necessity that defined the character's visual identity for decades.
Doug Parker voiced Mega Man in the animated series Captain N: The Game Master. Parker gave the character a tendency to add the prefix mega- to words for emphasis, such as mega-awful or mega-terrible.
Proto Man was originally known as Roll's brother and designed to be a more rebellious and stylish counterpart to the wholesome Mega Man. The rivalry between the two was not one of hatred but of contrasting philosophies, with Proto Man representing the bad boy style that many fans preferred.
A live-action film directed by Eddie Lebron was released in 2010. The film brought the character to the big screen using a mix of CGI and extreme sport equipment to depict the fighting robots.