Armor Watcher is a website where you can enter your gamertag and it will generate a custom gamercard or signature for you with your current spartan decked out in your chosen armor and colors, emblem, and a handful of stats.
Here is my gamercard, with the color cyan chosen:
CHa0s’ Halo 5 Generated Signature
You can also build a custom gamercard or avatar for Halo 4, or retrieve your avatar from Halo: REACH or Halo 3. And if you’d like to create your own signature using your spartan, Armor Watch has the tools to generate or build your spartan armor from Halo 4, Halo:REACH, and Halo 3.