Independent layers for steel and steel aux.??

I would try to change their MOS, or give other names than 6xx/wall...
But I cannot give you an exactly solution.

It's dangerous to work with 2 walls in the same place. There could be a reason to do that, but you should organize them in different floors. If they are in the same floor, there are problems with automatic wall intersection. Walls from different floors do not intersect with each other.

I think, the best idea is to work with different layers (-20...0...+20)

Example:
I made walls and created yellow glass insulation as panels between the posts.
All insulation is in slice 0, but in layer 15.
When storing the single wall drawing, I activated layer 15.
In my plan, now I have all insulation on DHPEbene15 (in German: Layer = Ebene).

BUT: Only the insulation, that belongs to the same wall, comes into this layer.
Maybe, there is other insulation, this would come in an other layer (DHPPlatte or DHPpanel?)

In the Timber Frame Editor you can define different slice and layer numbers.
It's not possible in the manual panel input menu. Parts from slice 0 are automatically added to layer 0. This is, what users normally want. You can activate all insulation, and manually change the MOS to layer 15.

You are not doing anything wrong. The steel has another color then the layer and so the steel did get a fix color but not the color 'from layer'.
You can switch off all layers exccapt the layer -15. Then you select the function to change the properties of the lines. Pick all lines with option 'window' and change the color.

I think, it's easier to change the steel color in Dicam by setting a 'steel filter' and set volume info: line color 'blue'.

That's right.

Activate all steel parts in your model (filters 9-7 may help you), then with Dicam 2-08 (volume info) change the line color of all active parts.

Now, when you make a storage and read it into a drawing, all steel parts will be blue.
Every part will have the same line color as it has in the model.

If parts have the same color as the drawing layer color, the lines will get the color "from layer". All other parts will have their "fix color". So later, when you change the settings of the drawing layer color, some lines will change, and others will keep their color.

puhh, I hope you understand my 'curly' English

Another interesting feature: If you don't want to spend your time with changing colors, you can once change 1 setting in Dicam 1-7-2.

Color sets can be defined in 2 two different ways:
- by type of beam: *100 (rafters) will have an other color than *600 (wall beams). I guess, you have this setting.
- by item number: the part will get the color, that is defined in the database item.

There would be a lot of parts to change, but only then, you have blue steel parts in every drawing.

alternative:
Steel parts are usually grey in the database. So, if you set the drawing layer to 'grey', all grey parts get the color "from layer". After reading the storage(s), you turn the layer color to 'blue', and all steel parts (and all other grey parts) will become blue.