minecraft-assets/data/minecraft/loot_table/shearing/sheep/red.json

{
  "type": "minecraft:shearing",
  "pools": [
    {
      "bonus_rolls": 0.0,
      "entries": [
        {
          "type": "minecraft:item",
          "name": "minecraft:red_wool"
        }
      ],
      "rolls": {
        "type": "minecraft:uniform",
        "max": 3.0,
        "min": 1.0
      }
    }
  ],
  "random_sequence": "minecraft:shearing/sheep/red"
}