I spent some time reading on the forums and researching, but I can't find a place explaining how to color or dye an avatar item. May I get some pointers?

you don't dye avatar items- avatar items generally have a few precoloured versions, and a rarer recolourable version

For example, the Cicada Aviator set comes in
Harlequin



Jade



Moonlight



and Plum



And the outfit, wings, and head piece have a recolourable version



(in sets that have them, Tails, Aspects, Cloaks, and Accessories may also have Recolourable versions. Helds and backgrounds do not)

Recolourable versions are depicted in greyscale and lack the name in brackets after the set piece name (eg, "Cicada Aviator's Uniform" as opposed to "Cicada Aviator's Uniform (Plum)")
(some sets have a slightly different naming manner but that's how it is for most. Recolourable will always have the base-most name)


With recolourable items you use the colour slots in the Outfit and Item tabs of the wardrobe's colour options to alter them

ah okay, thank you! that's all I needed to know =)