Here is an option to make your required dark shadow show on a dark background. This is done in Illustrator.
This is a radial gradient from black to gray behind the blue circle which has an attached dark drop shadow.
If there were an actual light source to provide the shadow then there would naturally be some light spill off onto the dark background.
SVG documents can only be in RGB as far as I know. They can be automatically converted to CMYK on export from InDesign, but you can't export to a spot color like that.
I would either:
Open the SVG in Illustrator. Change the colors to the wanted spot color. Save as an AI or PDF file and relink in InDesign.
Open the SVG in Illustrator. Select the logo and ...
I have a few suggestions:
Apply the dark shadow but don't worry much about it being not much visible. On fully dark black background (e.g. #000000), you can't create any dark grey shadow that's darker than background. It could be almost true in real world.
Also, you say it disappears completely, but I can still see some of it when I tried it. Maybe the ...
Yes, there is always a significant difference between RGB and CMYK whatever conversion you're doing.
Yes, RGB tends to be significantly brighter and/or more saturated, than the converted CMYK equivalent.
No, the final print on paper will not look like any of the RGB and CMYK variations on-screen. The end product will also look slightly off.
No, the designer ...
Use the personalized option and move each color selector individually.
Design is not a recipe, it should be a methodology, and fortunately, it still has one human component of "taste" and personal preferences.
Complementary does not mean an exact mathematical opposite. It is also relative, because there are many "opposites" depending on ...
Color theory, or atleast its naive implementation, is almost certainly somehow broken. Why?
If you are selecting based on a color wheel. Then your entire selection crieria is perdicated on the fact that the color wheel is correct. But you have many different color wheels. Thus many different selections are possible to fullfill the result it just depends on ...
Try (RGB) = (73, 152, 255) with 35% opacity. Numbers have base=10. No guarantee, I cannot be sure how close the shown image is to your original. Can easily cause 1 unit errors due roundings.
ADD: It's calculated with the well known elementary mix formula. RGB component A in top layer with opacity P and the same color component B as opaque in bottom layer ...