ActuallyAdditions/src/main/resources/assets/actuallyadditions/blockstates/brown_lamp.json

{
  "variants": {
    "lit=true": { "model": "actuallyadditions:block/colored_lamp_block_on_brown" },
    "lit=false": { "model": "actuallyadditions:block/colored_lamp_block_brown" }
  }
}