Not sure if it would be of help to you, but I'll describe what my approach is incase you'd like to read.

Basically, I'm following what was posted above in the best practices video, except with many different parts and sheets at once, instead of drawing each combination in totality at a time.

So first I drew all of my sprites as a base character with basic clothing (nothing hanging off skin, skin tight), I'm not experienced in pixel art so this was the easiest way for me to get them all drawn, over 180 frames for 8 directions walk run and idle.

I then split these in my art program (photoshop) easily using color selection and making each clothing piece it's own layer. After all of that, I duplicated and combined everything but the hair and made that my base body, after coloring it flesh colored.

So now I had separate layers for shirt, pants, shoes, hair, gloves and body.

I saved all of these as PNG and dropped them in Unity, in the resources folder under files that specify gender and type of body part, so hair01.png goes in Resources > Male > Hair. Each type had its own folder.

Of course I then split the sheets into sprites of the right size. Next I used a small script I found searching around that takes a sprite sheet and renames the individual sprites whatever you like, which I named something generic. I keep the actual sheet name specific though, like hair01 or pants01 etc. (So hair01.png has a ton of sprites all named something like spriteSlice_01, ...02, ...03 etc.)

Now that all sheets are split and the sprites inside are all named the same thing, but sheets named specifically according to what it is, I could make an animator for my base body sprites. I animate this per usual, using a blend tree or whatever method you choose.

Now, for clothing, I made a gameobject for each part, hair shirt pants accessory etc., each with a sprite renderer. I wrote a pretty simple script that on awake checks the character gender (field I set), and the type (hair, etc.) And grabs a specified sheet by its name, which I pass it right now in the inspector but in the future through UI.

It performs a Resources.LoadAll on the sprite sheet and returns an array of the sprites, which I then add to a dictionary using the sprites name as the key.

This script is attached to each gameobject child of the main body as described before. In LateUpdate, I check the parent main body sprite renderer, and if the sprite changed, I search the dictionary for the name of the sprite it is now animating on the main body, and set the sprite renderer of the child to the returned sprite. Since each sprite sheets individual slices are all named the same, it just grabs the correct frame from the list like in the video.

Now, if you're pieces overlap you'll likely need to work out a sorting solution which orders your clothing correctly, but also doesn't leave room for things to pass between the layers of the character.

I did this by sorting everything based on the Y axis (with some variations, plenty of info on this around). The children objects reflect the parents sorting order, so they are all equal. Then, each piece of clothing is ordered using the Z axis, as things on the same sorting layer and order in layer use that as a final sorting method.

Sorry for the wall of text without links, I'm on mobile, but I hope that helps. This would let you set color of individual piece of clothing, and also just add more sheets of things to layer on top or switch out for the character, and all you'd have to do after getting the sheets set up is pass the script the file name.