Fair Warning: this post is about 4.1 years old, so some of the information might be a bit dated. On the other hand, this post was last modified about 4.1 years ago, so maybe it's up-to-date after all. In any case, please keep all this in mind while reading. Thanks for understanding!
A Quick Diversion:  

The Actual News:

So with the release of the “The Crown Tundra” DLC pack for Pokémon Sword/Shield two days back, I’ve been carefully pouring over all of the new stuff that was released in it. And by “carefully pouring over”, I mean “hastily playing catch-up because I only just downloaded the DLC after forgetting all about it for two days”. Now there is already a ton of stuff I’ve found right away that is worth sharing, such as the Galarian names for Peony for example… but today I want to share the ColorDex entries for the “expedition scarves” that you get to customize your expedition uniforms with.

Specifically, after agreeing to babysit Peony while his daughter, Peonia, gets to hang out in the Dynamax Caves… Peony gives you your Expedition Uniform once you reach Freezington (which, for some reason, doesn’t have a town sign and thus no Galarian name… yet). Once you put your uniform on, you are able to customize it slightly by changing the color of the scarf that’s on your left arm. The colors available are one of each element type, plus one “Expedition” color. These type colors are basically the same as the colors you can choose for your bike outfit… which I keep forgetting to add to the ColorDex as well.

Anyways, I thought I’d do you guys the favor of showing you what each scarf color looks like, as well as the Hex color values for the scarves… just in case you wanted to draw yourself in your favorite scarf color in your favorite art program. Nifty, huh? Afterall, that’s the whole point of the ColorDex: to help artists choose the most accurate colors for each Pokémon type across every Pokémon game and generation. Huzzah! So with all that said, the list of the colors are below, sorted by type alphabetical order, and with the “Expedition” color listed last.

 Bug
#958D00 — #8C8400 — #6A5D01
Dark
#C2005C — #B60057 — #860033
Dragon
#062B56 — #062951 — #01153B
Electric
#E5D100 — #D7C400 — #A68E02
Fairy
#E0A5A0 — #D39B97 — #9C6969
Fighting
#DF5E00 — #D15800 — #AD4001
Fire
#C11415 — #B41313 — #910000
Flying
#3292C1 — #2F89B6 — #1C6589
Ghost
#9282C9 — #8A7BBE — #6A5991
Grass
#6A9C46 — #649342 — #4D6E28
Ground
#543200 — #4F2F00 — #3F1E00
Ice
#F3ECE4 — #E6DDD7 — #B7AAA4
Normal
#C2BFB9 — #B7B4AF — #958B89
Poison
#34D257 — #31C552 — #24A53F
Psychic
#A944A0 — #A04097 — #802A77
Rock
#9F9A9A — #959191 — #746B6E
Steel
#38575B — #345255 — #1E3439
Water
#3155BC — #2E50B2 — #1A388B
Expedition
#DF3506 — #D33206 — #AC1A01

And that’s that! Nifty stuff, huh? What I now wonder is why the type colors for the scarves (and, for that matter, the bike uniforms) are different relative to the type colors for the attacks. For example, the “Poison”-colored scarf is green, but Poison-type Pokémon and attacks are purple. Same with the Dark-type, where its attacks are not as vibrant of a purple/magenta as its scarf is. Maybe the artists for the CG models and the artists for the 2D graphic elements chose them on their own and neglected to check in with one another to see if their color choices match up? Whatever, this is a pretty common thing over Pokémon history anyways… just look at how many different colors have been chosen for the Dragon-type across Pokémon history: it’s run the gauntlet between green, blue, indigo, gold… I mean, I guess those could all be considered “Dragon” colors, from a certain point of view. Oh whatever.