Newbie question: rectangle fill - colours disappeared

Must have done something beyond my intentions.

Now when I draw a rectangle and then try to fill it with a color by clicking the fill square to the right on the tool option bar (the upper red rectangle in this picture I've lifted from the web)

I don't get a nice choice of many different colours but an almost empty dialog with just two patterns.

How can I reset the former normal behaviour ?

Thanks in advance