Mozilla Corporation member Deb Richardson gives us this thorough tour of the new trust indicators in Firefox 3. Apparently Firefox will have a five-tiered color scheme, which goes (in decreasing order of trust):
Green - EV SSL Certificate. Complete idenity known, both domain and organization.
Blue - SSL Certificate. Partial identity know. Domain only.
Gray - no information.
Yellow - invalid certificate. Deb's example includes a self-signed certificate.
Red - phishing site.
The careful observer will notice that this scheme is very similar to (though not identical to) IE7's four-tier system of green, "clear" (white), yellow, and red. The...