Hi! I'm often doing monochrome images (not sure if that's the correct word, illustrations where you only use different shades of one color, from 0 = white to 100 which would be the full color).

In Illustrator (+___+) you can do this quite easily with „global“ colors and it has the amazing advantage that you can also change the color and the different shades of it will change as well.

Is there a way to do this in inkscape?

If I understand correctly, I don't think so, exactly. 

I suppose if your workflow included initially setting a tag or class for objects using a particular color, e.g. "violet" (using the object properties), then all objects using that tag or class could be selected via find/replace and the HSL extension used.

Would that be useful?

There's an extension for that. [Extensions > Color > HSL Adjust...] will shift the colours of the selected objects.

Ohhh, that looks really good, thanks @Paddy_CAD

There's no way to mark this solved, is there?

This I can do.

Thank you ^__^