I have PhotoShop 2020 (v21.1) on a new 16" MacBook Pro running MacOS Catalina. I am measuring lengths with the ruler tool in photos, as I did without trouble on an older Mac and older PhotoShop version. The line it draws for the ruler is so faint (gray and 1 pixel wide) that it is virtually invisible on my photos, which are largely a similar color (they are DIC microscope images so colors are washed out). On the pulldown menu for the ruler tool, it says "No Tool Presets Definable for the Current Tool." Is it really impossible to change the thickness or color of the measuring line for better contrast with the image? Is this a problem with the higher pixel resolution of the display on the new MacBook? Help!