Each avatar has 3 layers: background, foreground (head), and text (single letter).

The background code chooses from one of the background SVGs (gradients in different directions with color placeholders) and then selects colors to put into the SVG. The whole things is meant to be easy to extend to fit your needs.

My understanding with Gravatar is that your email is hashed in order to select an avatar you have already uploaded, but is not used in customizing the avatar. Is that right?

What did you have in mind?

Also, what error do you get on Magicell? There are some geo-restrictions in place, so I am curious what you saw. Thanks!

IIRC Gravatar has an option to generate a default image if you didn't upload your own avatar. Imagine that the the has was 89A3 then the image was a 2x2 square with colors 8, 9, A and 3; using some number2rgb function so it was green, yellow, white and red or something like that. I'm making up the details! And they used other shapes and more than 4 parts, but I hope my description is good enough. I found some nice discussion with the details of the real implementation in https://meta.stackexchange.com/questions/17443/how-is-the-de...

A few years ago it was popular to make Gravatar "clones". One generate weird robots instead of geometric shapes. Another generated aliens. ...

In Magicell I get "403 Forbidden", I'm in Argentina.