Red, blue, yellow, and green are the four colours that make up the “square of squares” in Microsoft’s new corporate logo (note that these colours can also be found on the wings of the MSN butterfly).
Incidentally, they are the four colours found on the Mauritian flag (anti-clockwise) and has been used for more than two decades in various iterations of Windows up until Windows 7.
But there are also many other technology compies that do use the same colour scheme, albeit not necessarily in the same order.
Online auction giant eBay uses the same RBYG pattern for its own logo
Security company AVG uses a slightly less flashier scheme but still within the same colour style.
Google Chrome browser and Chrome OS both use the same four colours but in a circle rather than in a square.
Open source content management system Joomla has a different take but still uses slightly different hues of the same four colours.
And finally, another web giant, Google, uses these four same colours in its original, unaltered logo in the following sequence; blue, red, yellow, blue, green, red.