I started with this photo from the Rijksmuseum website, which provides high-resolution images free to use and modify for any purpose, in their Rijksstudio.

In iColorama, I used Adjust/Tonelab preset 4 for clarity and depth, and Style/Coherence preset 1 for smoothness.

Now to simplify the image for the "mostly color" version. I used Style/Simplify preset 10.

In Adjust/Vibrance, I increased saturation.

Now to make the "mostly lines" version. Returning to the unsimplified image, I applied Style/Water preset 9. Generally, I simplify before creating the edges or lines.

Now, to create edges, I used Style/ET-Flow. There is a huge amount of possibilities to explore in ET-Flow, so try the different slider settings, including the sliders under Settings. You can see that we got not only edges, but shadows as well. Also, rather than a black and white "mostly lines" image, as we've done in other images using this technique, here I've outputted a color image from ET-Flow.

In Effect/Blend,, I blended the ET-Flow image (the "mostly lines" image) with the saturated image (the "mostly color" image). I tried several blending modes and all the sliders.

I applied Adjust/Tonelab preset 4 to enhance the feeling of depth.

Now I want to add a touch of Effect/Raise. In preparation for that step, I smooth the image in Effect/Denoise preset 2 (for smoothness) and preset 4 (to smooth jaggy lines). For visual interest I used Style/Tensor preset 3 to add dots (low opacity, try different slider settings). Now I used Effect/Raise.