You'll notice a new link in the upper right corner of the website - titled "Buy T-shirts".
Here you can order a new line of WMS t-shirts. The same illustrations, but available in many different colours, including black! Mind though that the price as increased a bit, but the shipping costs have gone down.
There's also a link titled "Buy Gadgets". This takes you to the old online store where you can still order WMS gadgets - like keychains, iPad cases, backpacks, mugs,.... - aswell as the old, white t-shirts.