"צביעה באוכלים" (coloring in foods) - the stringent view of some poskim
putting New Shoelaces into Shoes, Inserting a String into a Hood, and Stuffing a Pillow;
measuring and weighing in cases of illness; measuring and weighing for a infant; using a thermometer;
is one allowed to wear glasses on Shabbos when the lenses change colors in the sun and indoors?