simple little yellow kde start button for your kbfx menu.
kde logo is the about_kde file from the kids icon set that can be found here: http://kde-look.org/content/show.php/KDE+4+Kids?content=9144
the shape of the button is the same as the shape of these buttons: http://www.kde-look.org/content/show.php/Led-kbfx?content=46200
created with GIMP
included are the *.xcf files so you can modify to your liking
edit: link to screenshot
so you can see what it looks like in action