New Master Yi Legend's colors are Calm and Order not Body.

Bold title I know, when we already have a Calm Body Legend. But look at the high-res art for the new Legends you can see they all have a main color in the background with a small amount of another color.

https://preview.redd.it/xfskl4bz5ang1.png?width=1920&format=png&auto=webp&s=fa74630d257cfdc53562ab2efbb1c5fa305a1a3f

https://preview.redd.it/vzbbmh2v5ang1.png?width=1920&format=png&auto=webp&s=680d8e7b644dfb2b65b839435ea3af59768e52a6

We can confirm this works with the 2 legends we already know the colors for: Vi is Red and Yellow and Vex is Purple and Green. So for the other legends:

Diana is Blue Purple
Pyke is Red Purple
Rengar is Red Orange

And last but not the least, Master Yi is Green Yellow.

Now I know the color is pretty faint, but it becomes much clearer if you compare the yellow that Master Yi has to the previous Green Orange vs Green Yellow Legends

https://preview.redd.it/gknqukb07ang1.png?width=3090&format=png&auto=webp&s=e46917d178def7b6254c9422931f6cd5b4598a45

I would like to thank "@RiftboundReport" and piltoverarchive for the images