Color   What it means

Red

The certificate is out of date, not valid, or has an error.

Yellow

The authenticity of the certificate or certification authority that issued it cannot be verified. This might indicate a problem with the certification authority's website.

White

The certificate has normal validation. This means that communication between your browser and the website is encrypted. The certification authority makes no assertion about the business practices of the website.

Green

The certificate uses extended validation. This means that communication between your browser and website is encrypted and that the certification authority has confirmed the website is owned or operated by a business that is legally organized under the jurisdiction shown in the certificate and on the Security Status bar. The certification authority makes no assertion about the business practices of the website.