Colored inks that work with technical pens are not easy to find and I am still not too sure they will work well with mine, but I am ready to sacrifice a pen to try this out anyway.
In the past I have worked with colored inks but with different pens - and the death rate of the pens was somewhat on the high side.
Next bit to tackle on this drawing is the fishnet stockings (some internet searches required for reference!) and I also have to decide where and what sort of shading will go on the walls.
I normally keep thinking how best to solve such dilemmas while continuing with the easy cross hatching bits.
The solution/s will come eventually...