+1 — I'd also like to know this.

The simple answer is yes. It's also backward compatible.

It's safe to discard the profile if the working space is the display space. But on wide-gamut devices this breaks the above rule for untagged images. They will have a noticeable color shift.

So the sane way is to either set the working space to sRGB and convert the screenshots from the display space to sRGB, or sacrifice the wide gamut and some color accuracy and just set the display space to sRGB in system preferences.

So does the recommendation that you shouldn't color manage your designs still hold up?

My article on that is 8 years old, and a lot has changed since then. Browsers were such a mess, and a lot of the macOS colour management policies were different. I really need to update the article, and probably write a couple more on the topic. It’s complicated, and still in flux.

Stuff was so broken back then, that I was far happier working without colour management, on a known sRGB display with sRGB targets (iOS, Android, web).

I think if you’re using an sRGB-like display, it can still be a good way to work, but it’s becoming an increasingly bad strategy.

If you work on a Display P3 or Adobe RGB display, or you use a mixture of displays that aren’t sRGB, you don’t have much choice — you should assign the sRGB profile to your documents. For most of your design documents, anyway.

Should I discard the color profile when I paste a screenshot in Photoshop?

Sometimes. :P

It’ll largely depend on what you’re checking, and where the screenshot has come from. As Vlad mentioned, if your screenshot is 8bit per channel, and opening it in Photoshop means it’s been passed through one or more conversions, there can be severe quality loss.

If I’m checking the quality of a gradients and low frequency changes, then I typically open screenshots and remove the profile (with no conversion). We don’t yet have high bit depth screenshots in macOS, even though the window manager does run at higher bit depth on some Macs.

If I’m just checking measurements, then it really doesn’t matter if the colours are incorrect. I try to be very pragmatic about how to handle this stuff.

I typically assign an sRGB profile to my design documents now, but even then, there’s issues. It really sucks how complex this is. Saying “you need to understand colour management” isn’t a good solution. :(

I wish our tools weren’t completely ignorant of the issues, or entirely based on print design. Neither strategy is a good one.

tl;dr Yeah, you should probably just assign sRGB to all your screen design documents. And, you should probably never sample colours from the screen. If you need to work out the value of a colour, you’re best going to the original artwork file or code (and in that case, hopefully you’ll know which colour space it belongs to).