This dialog opens when you do any of the following:
Click a specific color on language-specific subpages of the Editor | Color Scheme page of the IDE settings Ctrl+Alt+S.
Press Ctrl+Shift+A and search for the Show Color Picker action.
Use this dialog to find the exact RGB, HSB and hex values of any color component.
Click this eyedropper to navigate to the object and obtain its color RGB or HSB as well as its color hex values.
Use this area to select a color.
Stack of colors
This area displays colors that were last selected.
Move the slider upwards to make colors in the Color mixer area brighter; move the slider down to make colors darker.
Click this button to select a color from the Color Mixer area, or the Stack of colors.
Click this button to omit saving the color information.