minecraft-assets/data/minecraft/recipe/red_candle.json

{
  "type": "minecraft:crafting_shapeless",
  "category": "misc",
  "group": "dyed_candle",
  "ingredients": [
    "minecraft:candle",
    "minecraft:red_dye"
  ],
  "result": {
    "count": 1,
    "id": "minecraft:red_candle"
  }
}