Thanks for the update. I like the new one-colour icons, but on the retina screen of the macbook pro they look tiny and pixelated. The "previous" and "next" segment arrows are almost just a blur in the middle of their circle. The others are just jagged and a bit hard on the eyes as they seem out of focus.
MacBook Pro/Mojave/Metal look and feel and latest CT.
Please try increasing the font size of user interface via View > Font > User interface. The size of the icons will get larger too.
Thanks for the tip. I set the "font" at 17 and the icons are now a good size and less jagged.