For steel items in drawings I use the MT defaults to control the line colours used. However, when dealing with existing steel or timber etc where I need to show it on my General Arrangement drawings but less vivid than the steel, I use VisibleModelColour in my drawing style so that whatever colour I make it in the model is what gets used in the drawing.
Mostly this works well, but sometimes AS does not behave as expected and does not use the model colour.
This happens for holes and weld preparations, which have their own presentation rules in the drawing styles.
The timber hip beam below should be ModelColour according to my drawing style, but because I used a weld prep to chamfer top edges to make required profile, it shows blue (my MT default visible line colour).

Similar here with holes showing blue (my MT default visible line colour) rather than the model colour or the parent object.

Whilst changing the drawing style for weld preps and holes to use model colour would work in a particular situation, it is not a solution because if I do that, then weld preps and holes for my steel objects would be the wrong colour - I do not want these to be model colour.
If you add a notch or contour to a beam/plate, it changes the edges or cut outs of that object but they are still the edges of that object and will be the same colour.
Weld preps and holes should not be any different - they are just processing that change the outline of the object and should always be the same colour as the parent object in my view.