The Color Bar is shown below. You can hide/show the color bar from the Panels ribbon menu group in the main menu.

You can select the fill or pen/line color for selected object by clicking on one of the color buttons in the Color Bar.

Left click on a button to set the fill color.

Right click to set the pen/line color.

If the selected object can only have a fill color, or a pen/line color, then clicking the left or right mouse button will set the fill or pen/line color.