Layers are great for organizing a project. For construction lines alone I sometimes use 3 and more layers. And then there are more layers for each part I design. Each with its own colour.

And when a project gets bigger I start wishing for a quick overview in the layer list to the colours I use on them. So I wish for colour indicators on the layer list to quickly identify the membership of a line to a layer.

I have a small image attached to make you see, what I mean.