The great Spanish artist Pablo Picasso was known for his "Blue Period" in which most of his work was dominated by the color blue. Oddly enough, Deathstroke the Terminator also had his "Blue Period." In fact, he's had several of them. On multiple occasions, Slade dropped the familiar blue and orange getup and switched to blue and silver gear. So, let's take a short trip through Deathstroke's Blue Period(s).
The "Nuclear Winter" storyline in Deathstroke the Terminator (1991) #s 17-20 is our first stop. Deathstroke was dead (for the nth time) and his body was recovered by the Cheshire-led Brotherhood of Evil. Cheshire and company nurse him back to health and in payment for such a service, he has to join them. For whatever reason, Cheshire dresses Slade up in the costume you see below. He wasn't in this costume long, but it was long enough to be the look used for his DC Cosmic Teams trading cards.
The "Nuclear Winter" storyline in Deathstroke the Terminator (1991) #s 17-20 is our first stop. Deathstroke was dead (for the nth time) and his body was recovered by the Cheshire-led Brotherhood of Evil. Cheshire and company nurse him back to health and in payment for such a service, he has to join them. For whatever reason, Cheshire dresses Slade up in the costume you see below. He wasn't in this costume long, but it was long enough to be the look used for his DC Cosmic Teams trading cards.
Then, toward the end of "The Borgia Plague" storyline, Slade is caught in an explosion that all but destroyed his body. He somehow survived this, but lost his memories in the process. However his metahuman healing ability, pushed to the extreme (90s reference) to rebuild his broken body worked so hard that in addition to healing his injuries, it de-age him about 20 or so years worth. As part of his new start in life, as shown in the "Night of the Karrion" storyline, Slade adopted the blue costume pictured below. Notice the armor is absent from his chest and abdomen regions, but his shoulders, knees, shins, and crotch (Priorities, man!) are ready for combat. Deathstroke held onto this look for about three years.
The blue and silver look even made an appearance in the New 52 as Rob Liefeld revived it for an origin tale in Deathstroke (2011) #0, which is pictured below. Thankfully for us, Slade came to his senses and adopted the familiar blue and orange look we've all come to know.