In this preview, a part of the Image is displayed. A selection smaller than preview will be complete in preview. A bigger one will be cut out to be adapted to the preview.

If you middle-click inside preview , the clicked pixel color will be selected and will appear as From Color.

In this section, you can choose the color to be used to select pixels that will be concerned by color exchange.

Three sliders for RVB colors: If you have clicked on preview, they are automatically positioned. But you can change them. Each slider acts on color intensity. Input boxes and arrowheads work the same. Result is interactively displayed in the From swatch box.

Three sliders for thresholds, for each color. The higher the threshold, the more pixels will be concerned. Result is interactively displayed in Preview.

Lock Thresholds: This option locks threshold sliders which will act all the same.

Three cursors allow to select the color that pixels will have. Result is displayed in swatch box and in preview. You can also click on the color dwell to get a color selector.