I'm trying to come up with a PDF plot style that prints everything in black, except dimension lines and leader lines, which are grey. The following works for dimension lines, but not leaders:I'm just wondering if there's a set of component entities I have to look for instead, like with the dimensions?

I don't know, you should be able to override leader color like any other entity. - Wout

Looks like the colour gets overridden when the method is called on some private non-entity object that seems to contain the entity.