It seems that you chose a palette with so few colors (from the screenshot, I'd say it's the 'Tango' palette distributed with Inkscape) that there is nothing to wrap (wrapping happens for palettes which otherwise have a horizontal scrollbar if all swatches are displayed in a single line). Please try with the default Inkscape palette.
It seems that you chose a palette with so few colors (from the screenshot, I'd say it's the 'Tango' palette distributed with Inkscape) that there is nothing to wrap (wrapping happens for palettes which otherwise have a horizontal scrollbar if all swatches are displayed in a single line). Please try with the default Inkscape palette.