In Red White Yellow, the objective is to create groups of the same color in quantities of 6 or more by dropping the falling blocks into place. However, like its name suggests, Red White Yellow is also the order in which you must clear groups from play. It's a unique new twist to the new generation of falling block puzzle games popularized by Lumines.

Source: http://jayisgames.com/archives/2007/06/red_white_yellow.php