OK, so I have Mega Man on the brain these days--thanks to the recent announcement of Mega Man 10.
Anyway, in today's Mega Man-related news: Your Weekly Famicom has unearthed a rather interesting article from the Oct. 2, 1987 issue of Famitsu magazine. The article seemingly offered the Japanese populace the first glimpse of the original Mega Man (known as Rockman in Japan) game. The game wasn't called Mega Man/Rockman at the time, though--according to Your Daily Famicom, at that stage the title was called The Battle Rainbow Rockman.
That wasn't the first time the word rainbow was associated with the little blue bombshell--a post over at Protodude's Rockman Corner (say that three times fast) suggests the folks at Capcom considered calling the character Rainbow Man before copyright conflicts (with Toho Co.'s television superhero Rainbowman) convinced them to go with the less colorful Rockman.