#3 Selective color manipulation

[K-Bob]

Manipulate colors selectively for entire image,
shadows, midtones, or highlights. Radio buttons for
these four options, in the Color Dialog.

Probably would have to copy HSIchars.originals from
self when the radio button is switched. Would reset
still go back to original values when dialog opened? If
so, what happens when they adjust only the shadows,
then switch to entire image, and apply contrast change?
What's the input to the transfer function? The original
value when the window opened? That effectively wipes
out the changes they made to the shadows...