Updated: November 18, 2019
Here's a weird problem. I was using my Asus Vivobook, which happens to dual-boot Linux and Windows, and in the resident Windows 8.1, during some strenuous maintenance - installation of several applications, updates and such - my screen colors suddenly changed. It was as if the brightness had been halved, even though the slider was in the max. position.
I didn't discover what triggered this color muting, but I did realize that I needed to find a way to restore my colors back to what I like. And so I started fiddling a little with color adjustments and display calibration, and eventually wrote this tutorial, for things ain't (too) trivial. Thus, if you happen to be using Windows, and suddenly you find yourself disliking the colors on your screen, here's a tutorial that could help you.
Launch Color Management
Start the utility. Once it opens, take a few seconds to understand what gives. You could be using multiple monitors, and each one will be different - manufacturer, technology, lighting, resolution, etc. The wizard will let you detect all connected monitors, and you will have the ability to tweak each one separately. In my case, it detected the laptop's display as a generic PnP monitor. Do note that the specific version and configuration of your graphics drivers can also impact the color profile.
In the pane below, you will have one or more color profiles available. You can add new ones - by manually locating .icm files on your system, or remove the ones you do not like. You can then also select the desired one to be your default profile. Indeed, you can have multiple profiles, for example day/night work, media manipulation, video processing, gaming, streaming, etc. The changes are instant.
Calibrate Display wizard
On the third tab (Advanced), you will have the option to make additional changes to your different color profiles and the situations they apply to. Please note that you do need to understand what you're doing, to a degree, otherwise you will just blindly be changing things.
What we want is the Display Calibration section. If you click on the button, it will launch a wizard, which will ask you several questions, and show you several screens, where you will be asked to tweak the gamma channel, contrast, brightness, RGB channels, and alike. Some of the settings will be specific to your display device, i.e. you might not be able to tweak everything.
Once you finish the calibration, you will be able to compare between the current (previous) and your new profile, and then select the one you like better. Don't worry if you make mistakes, you can repeat the exercise as many times as you like, or remove color profiles.
In my setup on the Ultrabook, I had two Asus profiles, one dated to 2006 - way before the laptop was even created, and one dated to 2013. I couldn't really see any big difference between the two. After finishing the wizard, I had a third profile, dated today (the time I ran it), and it offered a significantly clearer, crisper display. I really don't know how and what went wrong, but at least I had a solid fix. Last but not the least, if you're not happy doing manual work, you can always check online for (other) color profiles from your manufacturer.
Once you complete the calibration wizard and apply the new profile, you will be asked to tweak your fonts. This is an optional step, and you can always skip it, but it might not be a bad exercise, as it can help you make the text looker nicer and crisper on your screen. The ClearType Text Tuner is another wizard, and it comes with five steps, where you will be asked to choose different sections of text based on their smoothness, sharpness, clarity, contrast and similar.
You may not necessarily see all the differences in the fonts shown above, because what you see will also depend on how your own monitor is calibrated. But there are definitely differences among the six snippets. Naturally, you should do this in the lighting conditions that best represent your typical work setup.
I am never happy when things go wrong without any clear symptoms that I can troubleshoot. This happens to be one of those examples. The best explanation that I can think of is that during my slew of updates and installs, one of the programs tried to launch the UAC prompt, which typically dims the background a little. Somehow, this didn't work out well, and I ended up with a color-muted display. But this sounds weird, and I am unable to replicate this. Moreover, the laptop's profiles are kind of dim, and I'm certain they had not been in use prior to this little glitch, because the change was sudden and noticeable.
The happy half of the story is that the resolution is relatively simple. This tutorial outlines the steps you need to restore/tweak the display colors the way you like them. There's a lot more to color management and profiles than what we covered here, but the basics plus the use of the calibration wizard should help you good results without any need for extensive, disruptive changes. Well, we're done. RGB away.