Monitor/Photoshop/Color profile issue

Question

heyz! yesterday i changed my monitor profile from srgb to prophoto rgb while viewing some images in photoshop. they displayed the same colors after the change, but today i opened photoshop again and with the same images and all the colors were dissaturated. ive done some search and found the probable cause is a ”broken” monitor profile, or one that doesnt match its capabilities. i changed to adobe rgb, reopened photoshop and that image seems to look right, but i think still not how i remember it from yesterday. my question is: is this really the problem and is there a way i can find whats the largest color space my monitor can display without reading its tech book?( cos its long lost)
thanks!
ps: when changing the monitor profile to prophoto i also played with color settings in ps and set it to prophoto/adobe rgb, but that image has an embedded profile and i chose preserve embedded profile when opening it, so i dont think thats the problem.

Answer 1

If there's a question here it's pretty vague. So, here's how it works, in general terms:
A monitor profile is a description of the monitor's native color space. And as such it also defines the gamut of your monitor. But the profile doesn't actually "handle" anything, it doesn't do anything - it's just a description.
Photoshop's color management system is where things are handled. Here, the document color profile is converted, on the fly, into the monitor profile, and these modified RGB values are sent to the monitor. That's all there is to it - a straight and perfectly normal profile conversion. RGB values are remapped to produce the same color.
Any profile can be converted into any other. But any colors in the source color space that would fall outside the target color space, are just clipped to the gamut limit, and they're effectively gone forever. If you have a ProPhoto file displayed on a standard monitor, it's reasonable to assume that a lot of gamut clipping has occurred before it hits the screen, because the monitor color space is a lot smaller.
A standard traditional monitor has a native color space that is very close to sRGB. That's why you can use sRGB as display profile, although of course a calibrator will make one that is much more accurate. This is also why sRGB is the standard for web, because it will display roughly right even without any color management.
Some monitors have a larger color space, and are close to Adobe RGB. These are relatively expensive and are known as wide gamut. If you have such a monitor, it can only be used with full end-to-end color management. In the absence of color management, sRGB material will not display correctly on these monitors, but considerably oversaturated. This is the implication you have to accept when you buy a wide gamut monitor.