Hi PeterUK,
welcome to this Apple (user-to-user) Community!
Re: "All I want help with is how to change the colour of an arrow or a line in Markup. There are many questions about this on here, but sadly no solutions as yet."
Am no expert in this area, yet your request deserves some response.
Wondering which app you are using Mark-up in, and whether you are using accessibility settings or not.
Eg:
To open the Markup toolbar in a supported app, tap
or Markup
________
For lines:
Write and draw in documents with Markup on iPad - Apple Support : While writing or drawing:
Eg: says:
Change the color: Tap a color from the color picker in the toolbar, then tap Grid, Spectrum, or Sliders to further adjust your color choice.
_________________________________________________________________________________
Also: For shapes:
Use Markup to add text, shapes, stickers, and more to documents on iPad - Apple Support
Eg: says:
Add a shape
- In a supported app, tap
or Markup. - In the Markup toolbar, tap
, then tap Add Shape. - Tap the shape you want to add, then do any of the following:
- Move the shape: Drag it.
- Resize the shape: Drag any dot along the shape’s outline.
__________________________________________________________________________
- Adjust the shape’s border color, border width, fill color, and opacity: Tap an option in the Markup toolbox.
___________________________________________________________________________
- Adjust the shape’s direction or dimension: Drag any green dot along the shape’s outline.
- Cut, copy, duplicate, share, or delete: Tap
next to the shape, then tap an option.
- When you’re done adjusting the shape, tap the screen.
- To close the Markup toolbar, tap
or Done.
____________________________________________________________________________________
Re: There are many questions about this on here, but sadly no solutions as yet.
Above info. for iOS 18: comes from: iPad User Guide - Apple Support
All the best :-)