Mastery Personalization
what if the level 2 and 4 rank reward for champion mastery was color customization? for each skin there was a Primary and Secondary color area that could be personalized as the mastery rank increased? lets say Secondary comes at R2 and Primary at R4
EXAMPLE

- Secondary - cape
- Primary - crystals

- Secondary - Staff
- Primary - Claw

- Secondary - Lantern
- Primary - Shovel

- Secondary - Hat
- Primary - Pix
So even people with the same champions would look different from one another. Each color can be any from the color wheel, and as bonus maybe you can set it to 'summoner spell color' or 'trinket color' so if u have Smite the color in question would be Yellow (then Purple/Red/Blue/White depending on upgrade), or if you have Sweeping Lens as a trinket, it'll be red, etc.