Open the spotlight toolbar,
image > spotlight
When the window is to narrow to fit all the buttons on the spotlight toolbar,
then two right pointing arrows shows up on the right side.

If one of the spotlight toolbar separators are outside the window then the arrows become black,

and when one clicks on them a white pixel shows up below the arrows.

If the window is wide enough to show all the spotlight toolbar separators, then the two arrows are grayed out and nothing happens if one clicks on them, even though there still are toolbar buttons outside the window.

The same type of arrows shows up on the main toolbar when the window is to narrow to fit all the buttons, if one clicks on them, then another toolbar slides down with the buttons on the left side that didn't fit on the toolbar.

To cancel the spotlight mode, one has to resize the window to show the whole spotlight toolbar,

because the cancel button is the right most item.
Changing the Red, Green and Blue input boxes into a color swatch like the one in,
Settings > View > Background color, would save some space on the spotlight toolbar.
