This test has been realized on Nexus 7 Original.
OG Nexus 7 (2012) display is quite under-saturated and generally dull.
Because of it's response curve (too bright) and also because of its weak gamut coverage: lacks in red, lacks even more in green.
In this example, I enabled Firefox Mobile color management support in about:config:
gfx.color_managmement.mode to 1
gfx.color_management.enablev4 to true
gfx.color_management.display_profile to /sdcard/og-nexus7.icc
Defining a color profile in software allows an application to alter the colors before they're sent to the lower levels and reach the display itself.
In the color-managed Firefox browser capture, you'll see that colors look over-saturated, especially Red and Green channels.
It's expected as applying the color profile compensate for the lacks of the display.
On the device itself, it looks just right and much nicer than anything the good old Original Nexus 7 is capable of usually.
A huge drawback today is that Firefox Mobile only renders content in 16-bit colors instead of 24, why you can see terrible banding in gradients.
Because of this, Firefox Mobile for Android is unusable for anything graphic related.
However, there's potential here.
Nightly built of the version 26 enables 24bit rendering!
It gives you and idea how color management, at OS or application level is useful, regardless of if you can actually calibrate the display hardware or not.
If the display is not calibrated, color management in software does all the work.
If the display is calibrated, color management in software will only compensate for hardware limitations of the hardware itself like typically the gamut size and coverage.