The default layer is blue, and all objects created in it have a blue name tag in the Layers and Objects dialog.

When working with lots of objects, repetitive clones, etc, it's easy to get lost.

It would be handy if it there was an option to have the objects names in the dialog of the same color as they appear on the canvas.

For example if I make a red sun with 60 rays using clones, every one of those "use####" objects should appear RED in the Layers and Objects dialog.

Instead they have the same color as the layer and I have to manually group them and change the color of the group. If this was done automatically I wouldn't even need to group them. I would know that every red use#### object is a sun ray. Then I could make a purple sun in a similar way, and its rays would be identified as use#### in the dialog

Is something like this possible?

I know I can avoid everything having the same color by using several layers because every layer has different color, but those colors are also preset and I would still have to change them to match what the layer contains, so it's not much different to creating groups inside one layer and coloring them.

Two options ( other than doing it manually ).

I have checked in Inkscape 1.3, seems the default single colour is the same. 

You could request this feature at https://gitlab.com/inkscape/inbox/-/issues

Or it could be written as an extension to change 

inkscape:highlight-color="#b4ee3b"

for each object / layer / group based on some criteria.

However this actually adds a line to the object in the document. The code is invisible to everything except Inkscape, so would not cause a problem, but would add bloat to the file.

Label colour based on object fill.

Alright at least we know its possible.

Another thing exists in the universe.

It won't work for gradients / filters etc.

Note it will overwrite any custom colours you have set yourself.

https://gitlab.com/inklinea/label-colours

Well extensions have never worked for me so I think I'll just make a request

Edit: Bummer, Gitlab doesn't allow anonymity and requires financial info just to register

I've raised a feature request:

https://gitlab.com/inkscape/inbox/-/issues/8758