There are no explicit Save and Load functions, however any changes you make should be reflected in the current URL. You can copy and paste the URL to "save" and "load" different builds. There is also the "Copy Equipment to Clipboard" button which exports a human-readable summary of your equipment choices. There is currently no way to inject that format back into the page though.
Missed the earlier question about what the colors mean. I've been meaning to add a legend, but in the meantime, the colors on your gear indicate whether a particular affix is currently relevant.
- Green is the best since that affix is the best and only one you have equipped.
- Blue means it's the best version but there's another piece somewhere with the same value.
- Orange means the affix is useless since there's a better version elsewhere.
When looking at the tracked attributes, the colors are different:
- Green means you have the best available value equipped
- Orange indicates a moderate value equipped (at least half of the maximum value IIRC, although that should probably be higher)
- Red indicates a very low value is equipped