You generally didn't--and still don't--see a lot of white on comic covers, and I always thought it frequently made for a nice cover.
The story: "Deadly Dreams of Doctor Destiny!" by Gardner Fox, Mike Sekowsky, and Bernard Sachs. Several JLAers have strange dreams where they are stuck with odd accessories, like a metal face mask or a mysterious ring--and then they are defeated by some of their foes. I wonder if this is a plot by the nefarious Dr.Destiny?
Roll Call: Superman, Batman, Wonder Woman, Atom, Hawkman
Notable Moments: The first time the Joker showed up in the pages of the JLA; Sekowsky makes him look paunchy and old--not exactly terrifying.
I always liked Dr.Destiny; he seemed like a great villain for the all-powerful JLA, even if he still is just a regular guy in prison greys.