This simple program has a few options and ways in which I use it.
Under the Menu item Opt you can ...
choose which colour space is displayed
in the program task bar area - the default is RGB
select the sample size (1,3x3 or 5x5
pixels) - the default is 3x3
stop/start monitoring (or press the
letter 's' as a toggle) - useful if you want to move your watched points
To start Watching a particular point, make sure the program is the active
one, and then when the mouse is in the desire location, press the letter 'a'.
Under the Menu item Watch you can clear all the watched points or just
which one to delete. New points are added in the next 'free' slot.
Because this is a simple program I can not draw lines to the watched
points. If you can not remember where they are, then move the mouse,
watching the x,y coordinates under the top left Hue clock, until they agree with
the x,y coordinates under the watched Hue clock. I also do not show the
before/after values of colours, but the border is the old colour and so if you
move the mouse over it, the left displays will show it's values!
To exactly see what is going on, you can make the display bigger/smaller by using
the Control key with '+' or '-'
(just like Photoshop image resizing). You may have to resize the window to see
everything.
I use the program in the following manner.
If I'm just using it as an eye-dropper/info display, then I have the program
window in the top left of the screen - thus...

but if I'm watching points, then (as I Ph-Arted the above dull picture), I
have the program window long and thin at the bottom of the screen - thus...

I would love to hear from you if you have found the program useful.