#include <QApplication>
#include <QPushButton>
#include <QStyle>
#include <QStyleFactory>

int main( int argc, char *argv[] )
{
QApplication a( argc, argv );

QPushButton btn( "aaa" );
btn.setMinimumSize( 20, 20 );
btn.resize( 200, 40 );

btn.setStyle( QStyleFactory::create( "Fusion ") );

//// #1
//btn.setStyleSheet( "QPushButton {\n"
//    "background-color: QLinearGradient( x1: 0.0, y1: 0.0, x2: 1.0, y2: 0.0, stop: 0.0 #008000, stop: 1.0 #ffff00 );\n"
//"}\n" );

// #2
btn.setStyleSheet( "QPushButton {\n"
    "background-color: QLinearGradient( x1: 0.0, y1: 0.0, x2: 1.0, y2: 0.0, stop: 0.0 red, stop: 1.0 yellow );\n"
"}\n" );

//// #3
//btn.setStyleSheet( "QPushButton {\n"
//    "background-color: QLinearGradient( x1: 0.0, y1: 0.0, x2: 1.0, y2: 0.0, stop: 0.0 rgb( 255, 0, 0 ), stop: 1.0 rgb( 255, 255, 0 ) );\n"
//"}\n" );

btn.show();

return a.exec();
}