w designerze klikasz prawym na push button -> edit style sheet
i wklejasz np
QPushButton {
/* Let's make the size of the button 1,5 times of font size. */
min-height: 1.5em;
/* Font size just 1.*/
font: 1em;
/* Margins so that we get a little space on the left and right. */
margin: 0 1px 0 1px;
/* The font color */
color: white;
/* Here's the background gradient with start point, end point,
stop "percentage" and color, stop percentage and color. */
background-color: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
stop: 0 #2198c0, stop: 1 #0d5ca6);
/* We'll round the borders. */
border-style: outset;
/* Round radius will be 3px */
border-radius: 3px;
/* Border is only one pixel */
border-width: 1px;
/* Border color is now set */
border-color: #0c457e;
}
/* This is style when button is pressed */
QPushButton:pressed {
/* We'll just invert the gradient by changing the colors around. */
background-color: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
stop: 0 #0d5ca6, stop: 1 #2198c0);
}
efekt niesamowity, sam to 1 raz wypróbowałem
wiedza zaczerpnięta -> http://developer.nokia.com/community/wiki/Archived:Creating_a_gradient_background_for_a_QPushButton_with_style_sheet