Is there any way to change the colour (sic) of the dimension lines, dimension text and arrows permanently?
Preferably GLOBAL but at least for the current document.
I am not comfortable with the default view at least on screen.
This can be addressed using the Object Styles docker to change the properties of the Styles that are used for Default Object Properties. There, you can:
As an example, in the Object Styles docker, under Default Object Properties section, you could select Artistic Text . On the Character tab, you could change the Font, Font Size, Fill, etc. to be what you want.
When you have "Artistic Text" selected there, then changing the properties in the lower part of the docker sets those properties for new Artistic Text created in that document.
If you want to save it as the default for Artistic Text in new documents, you can right-click on "Artistic Text", then click on "Set as New Document Default".
That example was for Artistic text. The process works similarly for Dimensions. Dimensions are sort of special in CorelDRAW because they involve multiple sets of properties:
Thanks. I thought I'd been down this route but I've just tried again and it has worked. I think I was not applying to selected and then setting as new document defaults. What ever, thanks again
Because a Dimension has Outline, Character, and Dimension properties, a really good way to manage the formatting is to use a "style set" that can control all of those styles.
Style sets can be imported and exported, and that can be a great way to "pay only once" when it comes to working out the details of formatting. Carefully set up one or more style sets in one document, and you can them import and apply them in another document.