"If the website has a certificate, the color in the Address bar shows the certificate's validation level.
The following table describes what the colors in the Address bar mean."
More at http://windows.microsoft.com/en-us/windows7/make-secure-transactions-in-ie9
From what I know this change carried on to later versions.
"Yellow
The authenticity of the certificate or certification authority that issued it can't be verified. This might indicate a problem with the certification authority's website."
My bet is some cert has expired.
Bob
In Internet Explorer and in Windows Live Mail I have had some unwanted color Changes since a couple of Days.
The change shows when for example entering a few characters in the address field. Internet Explorer then shows a couple of recent visited web services and the letters they have in common with what I just added is highligted in yellow (and therefore hardly readable).
Yes, I know IE is about to leave cyberspace soon, but the problem also occur in windows live mail where some external links from mails are yellow as well.
Anyone who knows where to change this back? Just send me your mail address if you want me to send a screen shot of the problem.
Regards,
Martin

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