diff --git a/matthewplotlib/colormaps.py b/matthewplotlib/colormaps.py
index 87a5cd9..1f50159 100644
--- a/matthewplotlib/colormaps.py
+++ b/matthewplotlib/colormaps.py
@@ -12,29 +12,30 @@
 ![](images/colormaps.png)
 """
 
-from typing import Callable
+from typing import Callable, Union
+from typing_extensions import TypeAlias
 from numpy.typing import ArrayLike
 
 import numpy as np
 
 
-# # # 
+# # #
 # COLORMAP TYPES
 
 
-type ContinuousColorMap = Callable[
+ContinuousColorMap: TypeAlias = Callable[
     [ArrayLike],
     np.ndarray,
 ] # float[...] -> uint8[..., 3]
 
 
-type DiscreteColorMap = Callable[
+DiscreteColorMap: TypeAlias = Callable[
     [ArrayLike],
     np.ndarray,
 ] # int[...] -> uint8[..., 3]
 
 
-type ColorMap = ContinuousColorMap | DiscreteColorMap
+ColorMap: TypeAlias = Union[ContinuousColorMap, DiscreteColorMap]
 
 
 # # # 
diff --git a/matthewplotlib/colors.py b/matthewplotlib/colors.py
index 1571299..7f4da9a 100644
--- a/matthewplotlib/colors.py
+++ b/matthewplotlib/colors.py
@@ -1,24 +1,27 @@
 from __future__ import annotations
 
+from typing import Union
+from typing_extensions import TypeAlias
+
 import numpy as np
 
 from numpy.typing import NDArray
 
 
-# # # 
+# # #
 # COLOR TYPES
 
 
-type Color = NDArray # uint8[3]
+Color: TypeAlias = NDArray # uint8[3]
 
 
-type ColorLike = (
-    str
-    | NDArray # float[3] (0 to 1) or uint8[3] (0 to 255)
-    | tuple[int, int, int]
-    | tuple[float, float, float]
-    | Color
-)
+ColorLike: TypeAlias = Union[
+    str,
+    NDArray, # float[3] (0 to 1) or uint8[3] (0 to 255)
+    "tuple[int, int, int]",
+    "tuple[float, float, float]",
+    Color,
+]
 
 
 # # # 
diff --git a/matthewplotlib/data.py b/matthewplotlib/data.py
index cfcd335..7661b25 100644
--- a/matthewplotlib/data.py
+++ b/matthewplotlib/data.py
@@ -1,7 +1,8 @@
 from __future__ import annotations
 
 import dataclasses
-from typing import cast
+from typing import Union, cast
+from typing_extensions import TypeAlias
 
 import numpy as np
 import einops
@@ -10,38 +11,38 @@
 from matthewplotlib.colors import ColorLike, parse_color
 
 
-# # # 
+# # #
 # Types
 
 
-type number = int | float | np.integer | np.floating
+number: TypeAlias = Union[int, float, "np.integer", "np.floating"]
 
 
-type ColorSpec = (
-    None
-    | ColorLike
-    | ArrayLike # uint8[n, 3]
-)
+ColorSpec: TypeAlias = Union[
+    None,
+    ColorLike,
+    ArrayLike, # uint8[n, 3]
+]
 
 
-type Series = (
-    NDArray                                     # number[n,2]
-    | tuple[NDArray, ColorSpec]                 # number[n,2], colors
-    | tuple[ArrayLike, ArrayLike]               # number[n]^2
-    | tuple[ArrayLike, ArrayLike, ColorSpec]    # number[n]^2, colors
-    | axis                                      # axis
-    | tuple[axis, ColorSpec]                    # axis, colors
-)
+Series: TypeAlias = Union[
+    NDArray,                                     # number[n,2]
+    "tuple[NDArray, ColorSpec]",                 # number[n,2], colors
+    "tuple[ArrayLike, ArrayLike]",               # number[n]^2
+    "tuple[ArrayLike, ArrayLike, ColorSpec]",    # number[n]^2, colors
+    "axis",                                      # axis
+    "tuple[axis, ColorSpec]",                    # axis, colors
+]
 
 
-type Series3 = (
-    NDArray                                             # number[n,3]
-    | tuple[NDArray, ColorSpec]                         # number[n,3], colors
-    | tuple[ArrayLike, ArrayLike, ArrayLike]            # number[n]^3
-    | tuple[ArrayLike, ArrayLike, ArrayLike, ColorSpec] # number[n]^3, colors
-    | axis                                              # axis
-    | tuple[axis, ColorSpec]                            # axis, uint8[n,rgb]
-)
+Series3: TypeAlias = Union[
+    NDArray,                                                      # number[n,3]
+    "tuple[NDArray, ColorSpec]",                                  # number[n,3], colors
+    "tuple[ArrayLike, ArrayLike, ArrayLike]",                     # number[n]^3
+    "tuple[ArrayLike, ArrayLike, ArrayLike, ColorSpec]",          # number[n]^3, colors
+    "axis",                                                       # axis
+    "tuple[axis, ColorSpec]",                                     # axis, uint8[n,rgb]
+]
 
 
 # # #