That's one of the neatest origin stories in all of comics. And yes the outfit was blue in that first tale. Steve Ditko and Joe Gill were at the top of their games when they created this iconic Atom-Age hero in Space Adventures #33 from 1960.
The story was reprinted later in Strange Suspense Stories #75 which after three issues of Captain Atom reprints became Cap's own magazine in the 1960's.
It was reprinted by Charlton again in the late 1970's in a revived run of Space Adventures.
DC Comics reprinted the story in its first Action Hero Archives some years ago in this decade.
Above are a some reprints of the classic cover image.
This story would take at least six months and as many issues of a full comic to tell today and it would still lack the power of this Charlton gem.