Do black backgrounds appear black, or do they have a red tinge to them? What about white areas? Are they white, or are they pinkish?
You might just need to adjust the bias/drive for the red gun. There are usually little pots for this, but I've never worked on a monitor as new as a D9200 - is that one of the ones with the on-screen controls?
It *could* be a cap - and if it were, it would be one in the video amplifier circuits. If the problem is really bad - where everything is very red and you have red retrace lines, then it's probably something with the picture tube.
I'm sure someone who has worked on a D9200 can chime in - again, my knowledge is limited to the 80's and early 90's era monitors. I know that some of these newer monitors have microprocessor controls and such - and looking at pictures of the chassis online, that is one massively complicated arcade monitor.
Do some more research and testing before you chuck parts at it. I'm not sure this is old enough to need a full cap kit.
-Ian