For an animation, every slot has a new color.
When I played this animation in Spine, the color appears correctly (on the character and in the Draw Order tree).
This color is in the .json file ({"Crete":{"color":[{"time":0,"color":"ffffffff"},{"time":0.0333,"color":"ff8e8aff"},...). But when the animation is played in unity (via skeleton.state.SetAnimation()), the color doesn't appear (with or without the code above).
Thank you for taking the time to help me 🙂