bedrock-samples/resource_pack/render_controllers/glow_squid.render_controllers.json

{
  "format_version": "1.8.0",
  "render_controllers": {
    "controller.render.glow_squid": {
      "geometry": "Geometry.default",
      "materials": [ { "*": "Material.default" } ],
      "textures": [ "Texture.default" ],
      "overlay_color": {
        "r": 0.0,
        "g": 0.0,
        "b": 0.0,
        "a": "variable.glow_alpha"
      }
    }
  }
}