One word to the creation process in case you want to join the team and want to create new icons. Or even a complete new set. I work with a 512 x bitmap first. And convert it to svg in size of 16 x 16 then. I try to use not more than 8 colors at time. But sometimes i still end in double size. No gradients. No transparencies.
The color palette that i use is a Gimp palette called Visibone. But i am open to any suggestions here. It just needs to fit together. That’s why you usually use a limited color palette.