I was wondering the viability of this idea...

I have an old (1997) Sony Trinitron 15" CRT monitor that I am not using.

If I use a NTSC->VGA converter, such as the viewsonic nextvision n4, would I get a useable output for video previews and color correction? Or would the color correction probably be so off that it wouldn't be worth it?

This idea came to mind because I saw the viewsonic nextvision n4 for $60 and the monitor isn't doing anything for me right now.

Color Correction requires a certified 'monitor' with Blue Mode only. Otherwise you are just color tweaking. So yeah it could be used for a TV out, but your color correction would not be accurate. Having a true NTSC TV helps editors to view colors and observe 'title safe' composition... your adapter may give strange results.

I'd probably just scrap it or use it as a secondary monitor for viewing email and webpages.