I suggest you view this page in a window wide enough that the images display in three rows of two images in each row.†
What the colour images contain
All the images contain 100% saturated colours. That is, the red blobs have (R, G, B) values (255, 0, 0), the green (0, 255, 0) and so on.
The first row images are in sRGB colour space, the second Adobe RGB, the third ProPhoto RGB.
The images on the left have the appropriate embedded profiles, the images on the right have no embedded profiles.
What this should show
On a normal-gamut monitor (not wide-gamut) then all six images should look the same or similar.† This is because normal-gamut monitors have a colour space that does not extend beyond sRGB (or not much beyond).† If all six images do not look very similar, colour management isnít working (or you are using a monitor with a gamut wider than sRGB).† Dodgy (or missing) monitor profile?† Browser or viewing program behaving badly?
On a wide-gamut, colour-managed monitor viewed with a colour-managed browser or program, the left images should be increasingly vivid (saturated) as you go down.† This is because each succeeding row of images is in a wider colour space: sRGB, Adobe RGB and finally ProPhoto RGB.† In each image, the colours are highly saturated, and the Adobe RGB image contains colours outside the sRGB gamut, and the ProPhoto RGB image contains colours outside Adobe RGB gamut.†
On some wide-gamut monitors whose gamut is little or no wider than Adobe RGB, then the left ProPhoto RGB image may look little different from the left Adobe RGB image, but both should look more saturated than the left sRGB image.†
If the left images all look the same, either you have a normal-gamut monitor or you are using a browser or viewer that doesnít colour manage properly (e.g. Edge or IE).
On a wide-gamut, colour-managed monitor viewed with a colour-manged browser or program, the three right-hand images should look the same as each other.† They contain no profiles, so the browser or program just has to guess.† Most donít bother, and simply donít colour-mange at all, and the result is that the colours will look like the bottom left image (that is, more saturated than the top-left sRGB image with the embedded profile).†
With Firefox, if you change setting gfx.color_management.mode to 1 (it defaults to 2) then the three right-hand images should all look like the top left sRGB image with embedded profile.† This option makes Firefox assume untagged graphics (with no embedded profile) are sRGB.
To my knowledge, neither Safari or Chrome have any similar option.† (To set that option in Firefox, you need to enter ďabout:configĒ (without the quotes) in the URL bar and search for setting gfx.color_management.mode.† Google for how to do it if not sure.)† Firefox is still the only PC browser I know of that colour manages properly, and also colour-manages untagged images (without embedded profiles).† IMHO itís the best browser for a wide-gamut monitor.†
Once again, Edge and IE are completely hopeless and donít-colour manage anything properly.†