(It's brown. Brown switches are best.)
I'm a lunatic who likes greys, but I can settle for browns. I prefer heavier over lighter. I also prefer tactile over linear, but I do so much work and leisure on my computer as somebody who has been working from home before it was cool that tactile just becomes a feeling I don't want to notice by the end of the week so I use blacks.
For people unfamiliar with mechanical keys:
Due to the dominance of Cherry MX keys they basically set the standard for everyone else and while other manufacturers might have different specs they tend to use the same relative comparison as Cherry. They categorize their keys by colour. Just by looking at the colour of the switch you can tell if it is tactile, clicky, or linear. You can also know how much force it takes to press down as well as how far you need to press the key before it registers as a keystroke.
Linear keys are generally the quietest and have the least tactile feedback, clicky keys tend to be loud and due to the design that allows them to make a distinct click sound they have about medium amount of tactile feedback, and tactile keys are all about that tactile feedback and you really feel when the key goes far enough to register. These three types are the main thing most people concern themselves over when selecting a switch. Usually the discussion is over brown, blue, or red which are tactile, clicky, and linear respectively and, IIRC, all require 45g of force to press down through their 2mm of distance to register and 4mm to bottom out. Blues might be 50g due to the clicky mechanism. These are fairly light keys and are by far the most popular. They are basically three versions of the same switch with slightly different feedback.
However, you can also find other colours which can be best described as copies of these existing switches, but requiring more or less force to press down and with more or less travel distance. Blacks are just reds you need to press harder. Silvers are reds that you don't need to press as far. Reds are a common basis to compare from online due to being fairly good for gaming for a lot of people. They slide very smoothly and are very light. A lot of people find the tactile and or auditory feedback of brown and blue switches to be distracting and unwelcome when they are quickly trying to press keys while gaming. Silvers are actually purpose made for gaming, but any theoretically edge for a shorter travel time is meaningless unless you're one of the best players humanity has to offer. I personally don't find the feedback distracting and actually find that it helps me be more responsive and more confident that any issues I am having are my fault and not some hardware acting up. That said you'll find a lot of people find red too sensitive so I recommend blacks for a best of both worlds.
Greys are browns that you need to push harder for the record.
Kevin has blues. Blues are loud as fuck. A lot of esports events allow you to bring in your own mouse and keyboard so long as you don't have any weird macros coded into them or extra buttons. This is so that you aren't being held back from a keyboard that is just an unusual shape or size for you or because your mouse has a different sensitivity feel than what you are used to. Yet almost all of these events ban blues and other clickies due to how loud, annoying, and distracting they can be. I almost feel bad for the rest of the household. Blues are a basic bitch switch. They are the baseline for clicky switches. I prefer the heavier greens if I want clicky even if they tend to be even louder.
There's only two reasons someone picks up blue switches: they are autistic and want the noise, or they didn't realize what they were getting and just got whatever was with the keyboard they picked. I can guarantee though that those keys are going to derive the rest of the household insane.
