In the colour selector window, you have a large variety of options for colour selection.
You can either type the code of the colour you want in HEX, RGB, HSL, or you can use the colour selectors.
The first colour selector tool allows you to select your standard colour and variations by moving the colour tool around the palette.
With the next colour selector tool, you can modify your colours by changing the RGB values or moving the sliders up and down.
The third colour selector tool lets you select from basic colours.
With the last colour picker tool, you can select the different shades of the colours you have chosen.