Incredibly awesome magic item for any rogue-type character. Especially if you count that it's Uncommon item, those bonuses are over the top!

Just out of curiosity, how much would making one of these cost in gold, and downtime?

Quote from crabman_joe >>

Just out of curiosity, how much would making one of these cost in gold, and downtime?

 About 500gp and a week

So would you expect to be in a Per v Ste contest where you'd have advantage AND your opponent would have disadvantage? What other item or spell lets you do that? Or would only one of those two be relevant in any given situation?

Looks like what is used before getting ring of invisibility. 

The One Ring, Hobbit

Quote from s0n0fz3us >>

So would you expect to be in a Per v Ste contest where you'd have advantage AND your opponent would have disadvantage? What other item or spell lets you do that? Or would only one of those two be relevant in any given situation?

 Stealth is used to either become hidden or to sneak past more passive observers (vs their passive perception). Perception check is when someone is actively trying to find you once you are hidden.

Well, there’s travel pace, where a slow pace can let players roll stealth checks to avoid detection while traveling. The players need to be moving forward, so they can’t be out of sight all the time, but a Cloak of Elvenkind can help the travelers blend into the environment. It‘s advantage can also mechanically be described as less helping you preform better, and more as covering your mistakes. If you’re hiding behind a grey rock, and a bit of green cloak ended up peeking out, enemies would notice and detect you. But if that bit of cloak could magically turn grey, even peeking out the enemy might not notice it. Not to mention that the cloak covers your back, and might help to hide you from a second patrol walking up behind you as you hide out of sight from a first patrol in front of you. 

I will say, I like your idea of a “Wood Elf” cloak. I don’t know why more magic items don’t give players ribbon abilities from the different races. The only one I can think of is the Belt of Dwarvenkind. 

I know when I’m playing a sneaky boi I always use the topography to decide where I’m hiding. I play exclusively non roll 20. So if we are in a dungeon I may hide in a shadowy corner or at the very least break line of sight with the enemies. Incidentally I also have that wood elf feature mask if the wild, that lets you try to hide in light obscurity. Because like you, I think hiding in the middle of an open field is stupid. 

this is a very interesting item to put in the game and it is very nice for any rogue character (like Anderty said). It is very useful for big crowds and a lot of other instances. If you have high Dex it is extremely good.

I actually don't think it's all that amazing for a rogue or any other character that is already stealthy. Sure, it is fairly powerful for low level rogues, but by the mid levels most rogues are already rolling stealth checks consistently in the 20s or even 30s. This just lowers the chance of any unusually low rolls. The cloak really shines on characters that aren't already stealthy, like a heavily armored character to balance out the disadvantage from plate, etc, as well as still providing their enemies with disadvantage on perception against them.

Quote from Lyxen >>

Actually, I find that I don't care for that object, not only is it very much overpowered (advantage for you and disadvantage for your opponent, too much for me, only one of these would already have been good enough, and it's only uncommon, I don't like this), but also, it does not provide you with any new opportunity to hide. So, to attempt a stealth check, you still need to be out of sight, so please explain how having a camouflaged cloak will help you be stealthy when you are out of line of sight ?

I will therefore, in my campaign, replace this with a cloak that provides you with the same benefit at the wood elves, the capability to hide in with only light obscurement, and I might throw it an advantage on stealth (may be for a "greater" version) if I'm feeling generous.

 

 

Beyond 20

 

 

 

 

 

 Interesting. Let me get this straight, and I mean this as respectfully as possible. So it’s too overpowered because it provides an advantageous camouflage for you when you want to hide and as a result the onlooker will find it more difficult to spot you. Yet it sucks because it doesn’t let you utterly disappear from sight while being observed or while lightly obscured.... as an uncommon item? I’m trying to figure out why you’re saying it’s so overpowered and at the same saying it’s so bad that it needs improvement. There are items that get more powerful than this that are in the same sort of category of effect.

It very clearly doesn’t help you be stealthy out of sight. The Boots that go with this could however. This item clearly states that it’s effective against being spotted essentially. Why is this good when you can only stealth while out of sight? Stealth is for sight and sound, and there are situations where a character may be out of sight and then cross briefly through an open area where they could be briefly exposed, it would be great for such a case. Or hiding in a sparsely vegetated environment. It really helps nearly any time a characters visibility comes into play. 

To me, the item provides a way of blending in a little more than say, not at all, by shifting colors to camouflage the wearer. As a result that’s an advantageous situation for the wearer and a harder, more difficult situation for an onlooker. The same mechanics are in place if someone tried to find a sniper in a field IRL and are in alignment with the rules for attacking/being attacked while relying on sight while the target is invisible. Advantage for the invisible creature making attacks and disadvantage for the creature attacking the invisible one.

It seems like your problem is not with the item but within the stealth mechanics themselves based on your comment about  having to stealth while not being observed. A good player will stealth long before they are ever being stared at. That said, you’re certainly entitled to your own opinion, and as a DM you are certainly within your right to change or disallow whatever you want. But given how powerful some items are by comparison, I think it fits into the higher end of Uncommon items very well. A D&D classic magic item.  :)

Actually 200gp & 2 weeks, as per xanathars:
requires: weavers tools, & arcana proficiency.

Can you dye this. I'm trying to dye it white and who has that ability and supplies in icewindale?

" as the cloak's color shifts to camouflage you." It's color changes automatically to suit your environment.

Just to say this doesnt have anything that gives advantage on Deception as it states in the notes

The tags are slightly ambiguous but I think are saying 'advantage: stealth, comma deception, comma outerwear' as 3 separate things

it magically changes color.... just make it white with its own magic  

Because you have the hood up, does it give you disadvantage on perception checks?

the advantage on stealth checks made to hide. is that the “Hide” action or just hiding in general as would be incorporated into the average stealth check?