Anker has just added the previously store-exclusive blue color option for the PowerCore Slim 5000 to Amazon! You can buy it here:
https://www.amazon.com/Anker-PowerCore-Fast-Charging-Perfectly-Smartphones/dp/B06XRWZMWH/ref=sr_1_1?ie=UTF8&qid=1491512187&sr=8-1&keywords=anker
Have a nice day, as always!