Eyedropper
With the eyedropper you can choose a color from the screen. Click with the left mouse button on the field under the color matrix and pull the cursor with the depressed button on the desired position. The eyedropper cursor can be controlled fine with the direction keys. The region under the cursor is shown magnified in the field. At the same time you can choose whether only one color is selected or whether to calculate the average value of 9 surrounding pixels. You can choose the mode with a right click.