type hint

tests/test_color.py

@@ -56,7 +56,7 @@ def test_hsv_rgba(self):
         truth = g.np.array([hsv_to_rgb(*v) for v in hsv])
 
         # they should match
-        assert g.np.allclose(ours[:, :3], truth, atol=0.0001), ours[:,:3] - truth
+        assert g.np.allclose(ours[:, :3], truth, atol=0.0001), ours[:, :3] - truth
 
     def test_concatenate_empty_mesh(self):
         box = g.get_mesh("box.STL")

trimesh/visual/color.py

@@ -29,7 +29,7 @@
 from .. import caching, util
 from ..constants import tol
 from ..grouping import unique_rows
-from ..typed import ArrayLike, DTypeLike, Integer, NDArray, Optional
+from ..typed import ArrayLike, DTypeLike, Integer, Iterable, NDArray, Optional, Union
 from .base import Visuals
 
 
@@ -455,7 +455,9 @@ def to_texture(self):
         mat, uv = color_to_uv(vertex_colors=self.vertex_colors)
         return TextureVisuals(material=mat, uv=uv)
 
-    def concatenate(self, other: "ColorVisuals", *args) -> "ColorVisuals":
+    def concatenate(
+        self, other: Union[Iterable[Visuals], Visuals], *args
+    ) -> "ColorVisuals":
         """
         Concatenate two or more ColorVisuals objects
         into a single object.
@@ -560,7 +562,7 @@ def __hash__(self):
         return self._colors.__hash__()
 
 
-def to_rgba(colors: ArrayLike, dtype: DTypeLike = np.uint8) -> NDArray:
+def to_rgba(colors: Optional[ArrayLike], dtype: DTypeLike = np.uint8) -> NDArray:
     """
     Convert a single or multiple RGB colors to RGBA colors.