Wow, go figure. Thats pretty much what I was envisioning.

Except it's pretty pricy. I was also thinking a clip-based device, but I can see how an eyeglass would also be good.

(I was thinking of a clip so you could have white balanced LEDs on the same and opposite sides of the ccd chip.)

But yeah, thats definitely the thing. Thank you!

https://www.nixsensor.com/ is another option in this space

There are lots of spot colorimeter/spectrophotometer devices. A more famous one is the Pantone CapSure. Unfortunately, while that device is calibrated, it's only going to match to the nearest Pantone certified color, as opposed to capturing and storing the color that was actually sampled.

Better spot colorimeter devices will have two different calibrated white LEDs and use both of them in sequence, to get a more accurate measurement of the true color of the object you're sampling.

The big trick with these devices is the color library that they're matching against. Sometimes you really do want to match against the Pantone library, and I don't believe any devices other than the official Pantone CapSure can actually measure against that library. But most paint manufacturers, etc... have their own color library, and there are a lot of other color libraries out there. And many of those libraries are exclusively licensed to only one particular spot colorimeter device.

So, sometimes you need to have multiple spot colorimeters/spectrophotometers in order to be able to use all the libraries you want.

Yes, I have several, including the Pantone CapSure and the ColorMuse. No, none of them are perfect. They're all missing one or more libraries that I might want to use.