Printing colour transparency coming out grey

[brucebob]

I am new to blender and luxcore, but I’ve manage to cobble together rendered protein structures that contain matte surfaces embedded in a hybrid coloured glass material that needs to be clear enough to see the embedded surfaces. Ive added a backing plane to ensure that the glass appears substantial. The renders on screen are great, and I’ve been satisfied with their appearance for a while, however, I need to create an image that looks good on screen but also prints nicely on standard colour printers. For the most part the expected colour shifts are fine, but the pale coloured edges of the surface print grey. Does anyone have any suggestions for adjustments I can try to ensure that the maintain at least a hint of colour in the physical print?

I guess the material of the backing plane could help here (its colour doesn’t matter since I am using a depth based alpha mask to remove the rendering). Adjusting the parameters of the surface seem to be a lost cause — making the glass less transparent obscures the embedded surfaces, similarly adjustments of the absorbance barely affects the thin edges.

Any help or suggestions would be welcome!

[AndreasResch]

That's one of those questions that leads to even more questions. And I guess that's not a Luxcore centered question, but an overall color management question.
For one, there's nothing like a "standard color printer(s)". And are you talking about a physical office printer or a printing company? But usually in both cases, subtle colors aren't the problems, it's usually the bold colors that give you headaches.

To begin with some images or and example scene might be a good start to better understand the issue. It's hard to find an answer when too many things are unclear - to me at least.

[brucebob]

Thank you for your response! Indeed, it *is* a colour management issue. The faint dark colours translated to CMYK values that incorporated too much black ink hence their perpetual grey-ness (I noted that bluer tones were indeed blue, so this was my first hint besides your response that this was the fundamental issue). Switching to RGB colours that better match standard CMYK colours that do not use black (at least on the transparent glassy surfaces on the render), yields prints that more consistently match what is seen on the screen. While magenta isn't normally my preference, it's aesthetic virtue in rendering images consistently on screen and in print is sufficient for me...

[PetrT]

In this case
may be this can help
1 make pics lighter
2 remove transparency by just dublicating main pic layer and merge it with copies until overall picture loose transparency

[kintuX]

Haven't read the thread, but Blender's default setting for Color Management: View Transform is Filmic > if so, switch to Standard.