Is it possible to change the  weight and colour of the preview of the lines that are drawn with the pencil tool? At present the line it draws is very fine, and a lime green; but my sons are both very colour blind and can barely see the line until they hit return and it changes to black. And so they can't see what they're drawing, which is making it very hard for them to produce anything at all. 

The bezier tool isn't quite so bad, as it's red, which shows up a lot better against the white background. But it's also a very fine line, and to be honest with my cataracts I'd like it to appear a little heavier if possible. 

I hope that all makes sense!

Adjust the tool to your liking: give it a certain stroke width and color in the Fill and Stroke tab - then double-click on that tool in the tool-bar to get to its properties - enable "This tool´s own style:" and hit "Take from selection" to make it permanent. There you have it. Have fun.

Thanks, Polygon, but that doesn't help. Yes, it makes sure the line is drawn as I want it to appear once I've finished drawing the line; but it doesn't change the line that first appears, before you make the line permanent. It's still that very narrow lime green colour then. 

Sorry - but this doesn´t make sense. Are you really following the steps from above?

This is what works in Inkscape 1.2 on Windows:

Open Preferences -> System, click the Open button after User UI.
This creates (if it's not already there) and opens a new ui folder in %appdata%\Inkscape.

Copy the original highlight-colors.css and style.css files found in the Inkscape install folder into this folder.

Edit the highlight-colors.css file with your preferred editor. Restart Inkscape to see your changes.

@Stitchy Hi, what @Polygon says should work fine. Just make sure that in the toolbar, in shape the none option is checked, because the other options works differently. Here is a short video.

Stitchy

but it doesn't change the line that first appears, before you make the line permanent

Correct - After all, you can't turn back the clock. But you can easily transfer the settings with "Paste style" to your new permanent setting.

Polygon's suggestion doesn't answer my question. His solution only changes the appearance of the completed line, which I already knew how to change. 

What I need to be able to change is the way the line appears as it's being drawn. It's currently a thin lime-green line while it's being drawn, which changes once I've finished drawing it to whatever I've set following Polygon's instructions. 

I suspect Aero's post is going to help me, and I'll let you know if it does once I'm back at my laptop.

Aero's method is working here in v 1.2, Linux Mint. 👍

Yes, Aero's post helped me. Thank you, Aero. That did the trick! 

I have the same problem that the original questioner had.

This is what works in Inkscape 1.2 on Windows:

Open Preferences -> System, click the Open button after User UI. ((My User UI Folder is EMPTY.))
This creates (if it's not already there) and opens a new ui folder in %appdata%\Inkscape.

Copy the original highlight-colors.css and style.css files found in the Inkscape install folder into this folder.

((These TWO .css files aren’t in my Inkscape install folder.))

Edit the highlight-colors.css file with your preferred editor. Restart Inkscape to see your changes.

((What TYPE of EDITOR would I need to Edit the .css files if I EVER FIND THEM?

((This is my 1st post and I'm not sure if I did it right, or not. GENE))

[Moderators have edited this message to assist in clarity]

artcreator1942

((These TWO .css files aren’t in my Inkscape install folder.))

Do a search or take a look in:
\inkscape\share\inkscape\ui
 

artcreator1942

((What TYPE of EDITOR would I need to Edit the .css files if I EVER FIND THEM?

Any text editor will do. (I used Visual Studio Code)