There is no reasons not to translate the "occurs" text which will be
in the color names in palettes extracted from images. It indicates on
how many pixels a given extracted color was occuring. We should also
translate the full string (not just "occurs") since some language will
have to reorder words, and may even use different bracket characters.
So I also add a translator comment to make sure the translators get
what the %s and %d stand for in this string.