LIghter colors or background overlay and "line" integration

This should be easy.

When using the overlay function while roasting, the colors representing P, D and F from the prior overlaid roast are so dark that I cannot make out the times at which I changed the values of those settings. Please make these bars a lot lighter.

Also, although you can see the precises times on the line curves above the bars because of the “dots”, there are no dots that appear on the bars representing the overlaid P, D and F bars. So you cannot tell precisely what time you may have adjusted P, D or F. Adding dots to the bars would cure this problem.