Powerful but tricky, moving arrows to the right, increase colour, to the left decrease it. You are concerned only with the precise position of the arrow on the threshold of data on the left of the histogram. You can move into negative numbers if you get to much of any one colour.

Colour Balancing should be done with positioning the cursor only 1 click at a time. If you were to move the cursors past the data threshold on the right, the histogram would disappear and the image would become black and white.