[eks391]

Get yourself a greyscale browser filter so photoshop isn't affected. This is the first result I got; I'm sure there are better ones

https://chromewebstore.google.com/detail/grayscale-screen/mc...

[Markoff]

it is much easier just to set up accessibility color filter and then toggle greyscale mode with Winkey+Ctrl+C and you can keep using your apps without installing anything