Does anyone know of a way to change the default highlight colors in the Preview App? I don’t like how dark they are and I’d like to change the yellow especially to something less goldenrod color and more bright yellow that you’d get with a real highlighter.
It’s a small thing, but it really bugs me. I also use the Touch Bar to apply highlights, so I’d like the default color change to apply to the Touch Bar as well.
In old versions of Preview you could change the color in the annotations menu or by right-clicking via a user-selectable ‘Other…’ color, but Apple removed the feature circa High Sierra. 
That’s been my experience too. I was hoping there was a way.
The free Skim pdf reader lets you choose your highlight color, but notes and highlights are saved in a separate Skim file, which might be a deal-breaker for some people.
That’s cool about Skim. My primary use case is highlighting things in my DevonThink database. The built-in pdf reader in DevonThink bugs me and I appreciate how when I highlight in Preview it holds and saves the notations back to DevonThink. So yes, for my use case, a separate file for notes and highlights wouldn’t work well. I guess I’ll just have to deal with the “goldenrod” color until we hopefully gain the ability to change it again down the road.