Google always had legacy versions
I've noticed since about a year ago that Opera 8, MSIE6, Opera 12 when searched from the bar, and Chromium were served different search pages. I've actually preferred the version with the black header because it loaded a tiny bit faster, and seemed visually more coherent, less "flat". Actually the Opera 8 no-frills version, only returning the search results themselves, was the fastest and preferable if given the choice.
The problem was that they were gradually removing functionality from the old page versions. The [Translate] link has been gone for a while from Opera 8. [More results from] disappeared later. The issue from their latest stunt now is that Image search in Opera 12 is completely broken. It is not possible to access the direct link to an image at all. Incidentally, Opera 8 image search is still working.
I've overriden the user-agent for www.google.com, and this returned the modern white style. However, the arrows for the [Cached] menus are not correctly aligned and sometimes are not clickable.
Google has almost arrogantly pulled a Microsoft here, artificially making their sites incompatible. I am afraid I will not be installing a Opera Presto onto computers anymore, with the exception for users who need a Mail Client. Tweaking user-agent is an unreliable short-term workaround. This move has influenced my decision way more than talk about abstract "security". Ironically, security was the whole reason why I had been preaching in favor for Opera, and often ridiculed for that. Win for Google and its cursed Chrome (I'll go with "Opera 25" in my case).