minecraft-assets/assets/minecraft/recipes/green_bed_from_white_bed.json

{
  "type": "crafting_shapeless",
  "group": "dyed_bed",
  "ingredients": [
    {
      "item": "minecraft:bed",
      "data": 0
    },
    {
      "item": "minecraft:dye",
      "data": 2
    }
  ],
  "result": {
    "item": "minecraft:bed",
    "data": 13
  }
}