What do the green and orange numbers under each field in the Bulk SEO editor mean?

The numbers are character counts, not limits, so long text still saves.

On Settings → SEO Settings → Bulk SEO Editor:

• Search title is measured against 60 characters and Search description against 160. That is about where search results cut text off.
• Green means the text fits. Orange means it is over the limit and will be cut short in search results.

Shorten the text if you want all of it to show, then click Save N changes. Only the title and description are saved. Prices, stock and everything else on the product stay the same.