Yellow username & pass fields in Safari?

[vetoes]

I wonder does yellow background in username & pass fields (Safari) means that information can't be read by any app or browser extension? I would assume that with grey version can. Can someone explain the difference?

 

[mfram]

Yellow means it was filled in automatically from your Saved web logins. Presumably you hit Touch ID or clicked the "key" icon to fill in your username and password.

 

[vetoes]

Thanks for your reply. Do you maybe know if information that is automatically filled is possible to be read by your browser extension or are they isolated?