Filled rounded rectangle

[Remi Delon]

Is there a way to obtain a nice rounded rectangle filled with a given
color ?
There is no smooth option for rectangles !
I can approach what I want by drawing a polygon with four lines
smoothed, but the shape is not the one I want.
I can get the shape I want by drawing the borders of my rectangle with
straight lines, and then using arcs for the corners, but then I don't
know how to fill this with a color !

Any ideas ?
Thank you.

Remi.