Simple color addjustment tool, very similar to HSVTool but gives ability to get much smoother color transitions since it uses curves.

I decided not to convert it as gizmo since its very simple and its important to be able to quickly connect "HSV_RANGES" node to viewer.

USAGE:

1. connect your image to "input" dot
2. Look at "RGB2HSV" node (connect it to viewer) and ctrl+click on color u want to change, your color is locked now (note that colors will be messed up since you will be looking at HSV colors)

3. now go to "RGB2HSV" node and you will see HSV values on lut graph (color that you have just picked)  (also dont get confused by using RBG channels, its actually HSV values)

4. adjust each channel curves so that "curve spikes" hit exactly where your picked color is (img2), also by adjusting curves you can be very acurate about how smooth your color will change

5. now just use "Color_adjustment" node which is just regular hueshift node to corect your color

Ivan