Items where the 2nd dye channel needs an adjustment.

[Heavenchild]

If I understood it right then the problem is that the dye channel is always tied to a texture like for example leather, fabric or metal.
The Adventuring Sweater seems to be two parts but I guess it's both fabric. Just the little accsssiore is another material.
That's why the second channel is tied to metall while the first is tied to fabric.

[dullneedles]

The Adventurer's sweater is one of the egregious examples but many of the statless glamour pieces have this issue. You could have a chest piece that has two separate elements that would fit perfectly with two dye slots, and it seems that a whole bunch of them have selected a three pixel button or buckle, leaving the other half of the piece undyeable. Like, did no one check these things for quality? Or did some intern write a macro on their lunch break and nobody followed up afterward? I feel like they could have put the budget into more impactful things, such as expanding on the character customization options in the Aesthetician