Suddenly (please check the pictures) it started happening
By going to preference and changing color theme, it brings everything back to normal, but not for long - until you move inserts places or go to next track.
What is going on?
I’ve experienced some theme-related weirdness too, but generally if you save the theme in Preferences, then close Nuendo out and re-open, things seem to be more stable. Try that and see what happens
And while we’re on the subject of colors, why did they remove the ability to type in RGB color numbers manually?
That I do not know, but the remedy that helps me with this problem is the following:
When I went to preferences where you select individual colors for various things, it shows squares filled with certain colors.
In my case all these squares were filled with nothing but “Grid transparency effect” chess board sort of a thing.
Basically each color square was fee of color - that explains why everything look colorless and black.
So I had to click on DEFAULT button to redraw all colors for each section of color preferences. Then I applies it and exit.
The problem fixed. But at some point it will happen again. So far, it’s happened twice 
The question is WHY this behavior occurred…
Could you please look at the attached image and tell me if this is normal for a color pallet in Nuendo 8.3 to look this way???
I have never ever seen anything like this. No wonder this weird thing happens with the whole color scheme.
I tried to kill all preferences and rebuild them… it shows the same thing.
Any ideas?
I’ve never seen that! Something is corrupted. I’d re-install…
I checked cubase 9.5
“Mix Console fader colors” it shows pallet the same way.
but cubase 7.5 - looks good.
I believe it has to do with the update…
Do you have nuendo 8.3 as well?
I have the exact same problem on Windows 10, N8.3. Never saw this before 8.3; was able to fix it by loading up a session in N7 and then loading the same session in 8.3 but something is definitely amiss. john
I upgraded to Cubase from 9.5 from 7.5then purchased nuendo 8
hoping that it will be a superb experience
In the end these upgrades ended up with more problems than previous version/s/ had.
Check out this: WHEN WILL THIS BE FIXED? - Nuendo - Steinberg Forums
I’ve contacted steinberg about other problems… no result. New updates come out and create new problems leaving old ones unresolved.
Unbelievable!
To the OP. I would recommend you add your system specs to your Signature. Very helpful to people trying to help you.
Without knowing what machine and OS you are on it is hard to make suggestions.