diff --git a/esphome/codegen.py b/esphome/codegen.py
index daf53db43fd..ec1ac161875 100644
--- a/esphome/codegen.py
+++ b/esphome/codegen.py
@@ -45,6 +45,7 @@ from esphome.cpp_generator import (  # noqa: F401
     static_const_array,
     static_function,
     templatable,
+    unique_global_id,
     variable,
     with_local_variable,
 )
diff --git a/esphome/components/light/effects.py b/esphome/components/light/effects.py
index 0b82a7d9b90..9bc60d79a7d 100644
--- a/esphome/components/light/effects.py
+++ b/esphome/components/light/effects.py
@@ -1,6 +1,5 @@
 from esphome import automation
 import esphome.codegen as cg
-from esphome.config import iter_ids
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_ALPHA,
@@ -30,9 +29,8 @@ from esphome.const import (
     CONF_WHITE,
     CONF_WIDTH,
 )
-from esphome.core import CORE, ID
+from esphome.core import CORE
 from esphome.cpp_generator import MockObjClass
-from esphome.helpers import ensure_unique_string
 from esphome.schema_extractors import SCHEMA_EXTRACT, schema_extractor
 from esphome.types import ConfigType
 from esphome.util import Registry
@@ -494,7 +492,7 @@ async def addressable_color_wipe_effect_to_code(config, effect_id):
             int(round(color[CONF_BLUE] * color_brightness * 255)),
             int(round(color[CONF_WHITE] * 255)),
         )
-        random_slot = NO_RANDOM_SLOT
+        random_slot = cg.RawExpression("light::NO_RANDOM_SLOT")
         if color[CONF_RANDOM]:
             random_slot = len(random_colors)
             random_colors.append(rgbw)
@@ -518,14 +516,7 @@ async def addressable_color_wipe_effect_to_code(config, effect_id):
     random_storage = cg.nullptr
     if random_colors:
         # One RAM slot per random entry; it starts at the configured color, as before
-        used = {str(i) for i, _ in iter_ids(CORE.config)} | {
-            str(i) for i in CORE.variables
-        }
-        id_ = ID(
-            ensure_unique_string(f"{effect_id.id}_random_colors", used),
-            is_declaration=True,
-            type=Color,
-        )
+        id_ = cg.unique_global_id(f"{effect_id.id}_random_colors", Color)
         values = cg.ArrayInitializer(
             *(Color(r, g, b, w) for r, g, b, w in random_colors)
         )
diff --git a/esphome/cpp_generator.py b/esphome/cpp_generator.py
index a5ffaefe0be..76d1db8d110 100644
--- a/esphome/cpp_generator.py
+++ b/esphome/cpp_generator.py
@@ -468,6 +468,17 @@ def progmem_array(id_, rhs) -> "MockObj":
     return obj
 
 
+def unique_global_id(name: str, type_: "MockObjClass") -> ID:
+    """A declaration ID for a generated global, unique against config ids, variables and reserved names."""
+    from esphome.config import iter_ids
+    from esphome.config_validation import RESERVED_IDS
+
+    used = {str(i) for i, _ in iter_ids(CORE.config)}
+    used |= {str(i) for i in CORE.variables}
+    used |= set(RESERVED_IDS) | CORE.loaded_integrations
+    return ID(ensure_unique_string(name, used), is_declaration=True, type=type_)
+
+
 def shared_progmem_array(
     name: str, type_: "MockObjClass", rhs: SafeExpType, *, share: bool = True
 ) -> "MockObj":
@@ -477,18 +488,12 @@ def shared_progmem_array(
     must be captureless. Its name is made unique against every config id and variable.
     ``share=False`` always emits a new array, e.g. for lambdas that may keep static state.
     """
-    from esphome.config import iter_ids
-    from esphome.config_validation import RESERVED_IDS
-
     arrays: dict[str, MockObj] = CORE.data.setdefault("shared_progmem_array", {})
     rhs = safe_exp(rhs)
     key = f"{type_} {rhs}"
     if share and (array := arrays.get(key)) is not None:
         return array
-    used = {str(i) for i, _ in iter_ids(CORE.config)}
-    used |= {str(i) for i in CORE.variables}
-    used |= set(RESERVED_IDS) | CORE.loaded_integrations
-    id_ = ID(ensure_unique_string(name, used), is_declaration=True, type=type_)
+    id_ = unique_global_id(name, type_)
     # Global, so any scope can use it; anything a lambda references is already declared.
     CORE.add_global(ProgmemAssignmentExpression(type_, id_, rhs))
     array = MockObj(id_, ".")
diff --git a/tests/component_tests/light/test_effect_color_tables.py b/tests/component_tests/light/test_effect_color_tables.py
index 1f20519674f..cf422bb0a7a 100644
--- a/tests/component_tests/light/test_effect_color_tables.py
+++ b/tests/component_tests/light/test_effect_color_tables.py
@@ -6,6 +6,10 @@ from collections.abc import Callable
 from pathlib import Path
 import re
 
+import pytest
+
+import esphome.config_validation as cv
+
 
 def test_effect_colors_use_flash_tables(
     generate_main: Callable[[str | Path], str],
@@ -26,4 +30,23 @@ def test_effect_colors_use_flash_tables(
     # Only the random entry gets a RAM slot, starting at its configured color
     assert re.search(r"static Color \w+_random_colors\[\] = \{Color\(", main_cpp)
     assert ".random_slot = 0," in main_cpp
-    assert ".random_slot = 255," in main_cpp
+    assert ".random_slot = light::NO_RANDOM_SLOT," in main_cpp
+
+
+def _color_wipe_colors(colors: list[dict]) -> list[dict]:
+    from esphome.components.light.effects import EFFECTS_REGISTRY
+
+    entry = EFFECTS_REGISTRY["addressable_color_wipe"]
+    return entry.schema({"name": "Wipe", "colors": colors})["colors"]
+
+
+def test_color_wipe_requires_a_color() -> None:
+    with pytest.raises(cv.Invalid):
+        _color_wipe_colors([])
+
+
+def test_color_wipe_random_entry_limit() -> None:
+    random_color = {"random": True, "num_leds": 1}
+    assert len(_color_wipe_colors([random_color] * 254)) == 254
+    with pytest.raises(cv.Invalid, match="At most 254 colors can be random"):
+        _color_wipe_colors([random_color] * 255)