I did my best to make recoloring Eulalie as easy as I could for Quest. Just about everything can be done in Unity alone. For the majority of the materials, you can simply select them in your Project tab and change the material's color.
I recommend duplicating the materials you plan on editing.
Here are the default hex codes for her outfit if you happen to lose them, though:
Blue (dress): C5E4FC | Pink (flowers): FFD2E5 | Pink (Particles): B88D97
A couple tips: You can shift+click adjacent materials to change their color all at once; or ctrl+click to select them one at a time. This works in-between folders as well (:
Here's an example of how to change the colors of Eulalie's outfit:
Body & Skin tone Changes
There are 5 variations of skin tone materials you can drag-and-drop onto Eulalie's body.
The "alt" versions have a separate texture for black eyebrows and lashes.
The Makeup materials are designed to be places on top of the eyelashes, and recolored to match the hair.
Here's how you can drag-and-drop the materials onto the model from the project tab:
You can also adjust the color of Eulalie's hair the same way you would with her outfit:
Eye Colors
The default texture for the eyes are pink. Since this can be a bit difficult to recolor on its own, there is an extra texture that is a bit lighter included in the "Quest Textures" folder. Otherwise, you can change the color the same way as everything else.
Particles
To recolor the particles, you have to open up the avatar's hierarchy and select the following objects:
Afterward, change the Start Color of the particle system to whatever you'd like.
If you are recoloring the particles to be on the darker side, I also recommend changing the shader on the petals, sparkles, and hand spawner materials from "VRChat/Mobile/Particles/Additive" to "VRChat/Mobile/Particles/Multiply."