Jack Kirby's Boy Commandos #1 Times Two
The Boy Commandos by Joe Simon and Jack Kirby were introduced in 1942's Detective Comics #64 and they were awarded their own comic book in less than a year. The cover of their first solo issue is seen above (with its bold and daring color scheme), and that series ran 36 issues before ending in 1949.
The boys were not seen again in comics until showing up in backup reprints in 1972 issues of Mister Miracle, and those led to them getting their own two-issue reprint series in 1973. The cover of that first-of-two-issues is seen below (with its crystal-clear color scheme). Please don't ask me which coloring I like better because I think they're both superb in different ways!
Of course there's another difference between the two covers. I never before gave any thought to the five gunners that were added in the foreground of the newer version, but now I'm crazy-curious to know who drew those figures. E. Nelson Bridwell edited the two-issue series and the cover to the second issue was drawn by the unusual team of Carmine Infantino and Joe Orlando, but those facts offer no insight as to the artist responsible for these bad guys. Ideas, anyone?
(UPDATE! The answer to this intriguing riddle has been discerned and you'll want to read it over here!)