B&H has a special going on the X-Rite i1Display Pro colorimeter which is what I use to calibrate my computer monitor. Now this is not to be confused with a legitimate color managed workflow that colorists use (at many thousands of dollars), but for those of us that are enthusiasts or one-person crews, calibrating your computer monitor will at least get you into the ballpark and ensure you produce reasonably consistent color on your video and photo projects. And now, you can pick this up for less than $200 US. It comes with X-Rite's Profiler software and calibrates your monitor quickly and easily. Here's a recent episode where we showed the process on my Mac. (also works with Windows):
https://youtu.be/Q7jrIWVBD98