What kind of cryptography is this

In a website called "Chatzy", when you post a message you send a POST request containing the message and your name and color, the name and color are sent in this form

MzEwMzk4ODgyNTIxNTQmMzEwMzk4ODgyNTIxNTQmMCZYMTY4JjE0MTE4NjkzNDUmSVFTQVhZT1MmRXZl​cmdyZWVu4oCMJjMyQ0QzMiYmMSYzJjEmdWJ1Z2dAemV0bWFpbC5jb20mZ3JpbTMyNzFvaCYxNDExNjAz​NTI5JiYyJg%3D%3D

That code gives the name "Evergreen" in this color http://ift.tt/1vJdjCc and here is the post in HTML

<P class="a"><B style="color:#32CD32;">Evergreen‌</B>: derp</P>

Can anyone tell me what that kind of cryptography is? I can provide more information if needed.