The top section of the Image Views tab is labelled Colours It allows you to select colours for the display that are easily visible over the colours of the image with which you are working.
The small graphic screen displays a section of your current image to help you determine if the colours selected will be visible over the image. If you want to check visibility over a different area of the image Click and Hold the left (forefinger) Mouse Button somewhere in the image. Moving the mouse will then drag the image with it. This movement is not restricted to the little graphic window, you can drag the image all over your screen as long as you continue to hold the Mouse Button down.
To change a colour click the colour patch beside the element you wish to change and select something appropriate from the pallette offered.
The check boxes to the left of the list of on-screen items control whether that element is displayed at all.
The Precision section allows you to set the number of decimals displayed on screen (to reduce screen clutter). These settings have nothing to do with the precision with which the transformation is calculated.
The Buttons are the same on both tabs: