I see that Mockup uses the Apple pencil default toolbar. It would, however, be great if we could change the default colours in the toolbar, but Apple does not allow those to change. Wireframes work well with different greys, so I would love to be able to have quick access to different greys and not have to open the colour palette every time.
Welcome to Mockup Community!!
It is true Mockup uses the Apple Pencil default toolbar regarding the colors with the presence of a color palette.
Regarding you suggestion of having quick access to different greys, it’s not available in the meantime but we have future plans on how to incorporate such idea. But again not in the meantime.