screen calibration device advice

Hello, I'm a student seeking a little information to aid with some research/study I'd like to do. I think this forum might be a good spot to ask, since a lot of you deal with color calibration on monitors.

I know that there are myriads of devices that are essentially colorimeters made to put on a screen and calibrate a monitor.
For my paper I'd like to study a few screens and see the actual level of color variance on those screens (before any calibration).

Basically as an example I'd like to be able to put a device on the screen, make the whole screen show #FF0000, and get the real world output as the colorimeter reads it (example: maybe it reads #FE1008 because the monitor has a slight color tint).

It seems obvious to me that, from a hardware perspective, these screen calibration devices are capable of accurately taking that sort of measurement. However, from a product/software standpoint I don't know if any of them expose that information! From what I can tell most of them just run as wizards for their intended calibration purposes and don't let you just use the device as a basic colorimeter.

I attempted to do this already with a "color muse" colorimeter (made for identifying things like paint colors), but of course it was not optimized for reading screens and gave obviously washed out values when tried on screens.

I'd like to avoid buying 20 different colorimeters made for screens just to figure out if one of them has software that will just read and expose raw color values. So what I'm hoping is that one of you may have experience with some of them and can confirm or deny whether any of the screen calibrating colorimeters on the market come with software that lets you access them as simple colorimeters and let you know the color they're currently reading on any given screen.

Any guidance is appreciated! Thank you!

You may want to contact the pre sales support teams at Datacolor, www.datacolor.com/ , and Calibrite, calibrite.com/us/ . Both make high quality monitor calibration tools. They may have a tool that you can use or point you in the right direction.