I've honestly only seen a photo of the Cullen version in color from TV Guide which I posted awhile back:
http://www.golden-road.net/index.php?topic=22616.0Still, I don't know why they didn't make the set more "color friendly" since honestly a gray curtain will look just like that in B&W of course, and a tan contestant's row, while interesting, doesn't have the same effect as individual podiums, though it took three years into the current run for that to happen.
I've never been aware that clips of Cullen in color exist, and most likely come from a special. However, although color tape was introduced in 1958, it wasn't until the later part of 1964, after NBC dropped Price that color tape saw a notable increase in use, and then in 1965, RCA's TR 22 and Ampex's VR 2000 finally made tape on color a practicality. Early color tape also was notable for degrading quickly, even as soon as the second generation of dubs.
Of course, the reason why a number of Cullen episodes exist in the first place is for the small, remote markets that didn't have connectivity yet to the main network of TV stations, and thus had to use kinescopes for broadcasting their shows. Of course, the very beginning of the run was live, and when the show went to "live to tape" circa 1960, early videotape was extraordinarily expensive, and thus wiping was by far the more practical solution, even among primetime shows, and thus all we were left with for the most part are the kinescopes. It was even worse at ABC, which wasn't quite comparable with CBS and NBC until the '70s, and since there were fewer ABC stations at the time, fewer kinescopes, and of course ABC never broadcast in color of course (I don't know of any other TV show that "downgraded" after the switch to be quite honestly). The earliest game show series where a considerable amount of color episodes exist is the last year of the original Password (albeit edited down a couple minutes for syndication).