レイヤーカラーのカスタム

Thank you kindly!
I know about that feature but I'm hoping to select more colours, I use Photoshop to create illustrations and sometimes the default colours are not enough.

You can apply a color label to a layer by right clicking on a layer:

After color labels have been applied, you can filter by them too by changing Kind to Color in the Filter dropdown menu and then selecting the color of the label you want displayed.