Apple Color 1.5 - Manual (Page 218)

If the highlights are too bright, you can lower the Highlight slider to bring them back
down, without worrying about crushing the blacks.
Overly bright highlights are often the case with images shot on video, where super-white
levels above the broadcast legal limit of 100 percent frequently appear in the source
media (as seen in the previous example). If left uncorrected, highlights above 100 percent
will be clipped by the Broadcast Safe settings when they're turned on, resulting in a loss
of highlight detail when all pixels above 100 percent are set to 100 percent.
By lowering the white point yourself, you can bring clipped detail back into the image.
Note: Values that are clipped or limited by Color are preserved internally and may be
retrieved in subsequent adjustments. This is different from overexposed values in source
media, which, if clipped at the time of recording, are lost forever.
218 Chapter 9 The Primary In Room