Microsoft is changing its corporate logo for the first time in 25 years. As the Metro-ification of the company continues, Microsoft has revealed a new logo that reflects its new approach to visual design.

For the first time in its history, Microsoft has a graphical symbol as part of its logo. Four colored squares sit to the left of the company name written in its Segoe typeface. Segoe is the font family of choice for Metro applications.

The new logo is extremely simple. The old logo had some nuance, with the way the 's' takes a notch out of the 'o'. This is now gone, though the ligature of the 'f' and 't' is retained.

This is Microsoft's fifth corporate logo. Its very earliest logo, used between 1975 and 1979, was a product of its time, a disco logo for the disco generation. Back then, the company called itself "Micro-Soft," a feature reflected in the split name.

In 1980 the company sold consumer-oriented products with a short-lived logo that was just a spurious umlaut away from being a heavy metal band.

In 1982, Redmond rolled out a new logo, all upper case with a weird patterned 'o' that came to be known as the 'blibbet'.

To the chagrin of many blibbet fans, that logo too was replaced. In 1987, the company switched to its longest-lived logo, the one it used until today. This was a much simpler, less ornate logo than any of the predecessors. It was the first to use mixed case type, with only the notched Pac-Man-like 'o' offering anything unusual.

The design of the newest logo, or specifically its symbol part, is more than a little surprising. Earlier in the year, Microsoft revealed a new Windows logo. Office 2013 also has a new logo. Both of these logos share some design cues, in particular, the use of a perspective effect on their symbols.

This perspective effect is a little odd in the context of the Metro transition, because it implies a kind of fake depth—precisely the kind of fakery that Metro eschews.

The new symbol, however, is flat; a square of squares. While this makes it a better match for Metro aesthetics, it also means that it has no visual connection or association with the other new symbols. The Office and Windows symbols are clearly related; the Microsoft one is not.

Also strange is the use of color. The colors and their positioning are more than a little reminiscent of the old Windows symbol. It's as if Microsoft has taken the old Windows branding and decided to use it as part of the new corporate branding.

To those familiar with the company's old branding, the new logo looks strangely mismatched: the symbol says "Windows" but the logotype says "Microsoft."

The company says that the squares of color are "intended to express the company’s diverse portfolio of products." A more cynical view might be that they're intended to reestablish the immediate name recognition that was lost when the new monochrome Windows logo was revealed.

The new logo is already being used on the microsoft.com site and three of the company's stores. It will be rolled out more widely over the coming months.