Paint.NET :: Modifier Keys Temporarily Highlight Selected Pixels

When working with selections - particularly when adding multiple Magic Wand selections to build the selection required - it can be difficult to see clearly (from the shading and outlines which show the current selection) what is selected already and what isn't - particularly at some zoom levels and depending upon the colour(s) of the pixels that you are working with (blue-greys, for example).

My suggestion, therefore, is that in any of the Selection tools, while you are holding down either of the modifier keys Ctrl or Alt (which would modify the Selection Mode of any further selection to Add or Subtract mode), all currently selected pixels should be temporarily highlighted - overridden by a single colour (say, your current primary colour?) with the shading (and outlines?) that normally depict the currently selected pixels removed. This would make it easy to visually confirm exactly what pixels are currently selected.

Perhaps the removal of outlines ought to depend upon the magnification that is currently being used: at high magnifications where each pixel is depicted by a relatively large screen area and the outline can be easily distinguished from the interior of each pixel, then outlines (perhaps of your current secondary colour?) might work to define the selected area, but where pixels are very small it might be best to remove them.

Also, as a visual indicator/reminder of the modification which the modifier key will make to the effect of the next selection - and one that is slightly larger than the minuscule plus or minus sign that appears in the mouse pointer - would it be easy to temporarily override the Selection Mode symbol showing in the tool selection toolbar, with the symbol for the modified effect, whenever the modifier key is depressed?Not forgetting that this symbol ought to change again if the Right Mouse Button is used instead of the Left.

If the above is easy, then, in the Magic Wand tool, could the Flood Mode symbol in the tool selection toolbar be similarly temporarily overridden with the Global Flood Mode symbol, when the shift key is used to override Contiguous Flood Mode?