diff --git a/manimlib/mobject/coordinate_systems.py b/manimlib/mobject/coordinate_systems.py
index c8352532..c51bf4cc 100644
--- a/manimlib/mobject/coordinate_systems.py
+++ b/manimlib/mobject/coordinate_systems.py
@@ -770,13 +770,6 @@ class ComplexPlane(NumberPlane):
                 axis = self.get_x_axis()
                 value = z.real
             number_mob = axis.get_number_mobject(value, font_size=font_size, **kwargs)
-            # For -i, remove the "1"
-            if z.imag == -1:
-                number_mob.remove(number_mob[1])
-                number_mob[0].next_to(
-                    number_mob[1], LEFT,
-                    buff=number_mob[0].get_width() / 4
-                )
             self.coordinate_labels.add(number_mob)
         self.add(self.coordinate_labels)
         return self
diff --git a/manimlib/mobject/mobject.py b/manimlib/mobject/mobject.py
index 7cd027d1..687f96f8 100644
--- a/manimlib/mobject/mobject.py
+++ b/manimlib/mobject/mobject.py
@@ -52,7 +52,7 @@ SubmobjectType = TypeVar('SubmobjectType', bound='Mobject')
 if TYPE_CHECKING:
     from typing import Callable, Iterator, Union, Tuple, Optional, Any
     import numpy.typing as npt
-    from manimlib.typing import ManimColor, Vect3, Vect4, Vect3Array, UniformDict, Self
+    from manimlib.typing import ManimColor, Vect3, Vect4Array, Vect3Array, UniformDict, Self
     from moderngl.context import Context
 
     T = TypeVar('T')
@@ -163,7 +163,7 @@ class Mobject(object):
     def animate(self) -> _AnimationBuilder:
         """
         Methods called with Mobject.animate.method() can be passed
-        into a Scene.play call, as if you were calling 
+        into a Scene.play call, as if you were calling
         ApplyMethod(mobject.method)
 
         Borrowed from https://github.com/ManimCommunity/manim/
@@ -287,10 +287,7 @@ class Mobject(object):
             about_point = self.get_bounding_box_point(about_edge)
 
         for mob in self.get_family():
-            arrs = []
-            if mob.has_points():
-                for key in mob.pointlike_data_keys:
-                    arrs.append(mob.data[key])
+            arrs = [mob.data[key] for key in mob.pointlike_data_keys if mob.has_points()]
             if works_on_bounding_box:
                 arrs.append(mob.get_bounding_box())
 
@@ -1323,20 +1320,19 @@ class Mobject(object):
 
     def set_color_by_rgba_func(
         self,
-        func: Callable[[Vect3], Vect4],
+        func: Callable[[Vect3Array], Vect4Array],
         recurse: bool = True
     ) -> Self:
         """
         Func should take in a point in R3 and output an rgba value
         """
         for mob in self.get_family(recurse):
-            rgba_array = [func(point) for point in mob.get_points()]
-            mob.set_rgba_array(rgba_array)
+            mob.set_rgba_array(func(mob.get_points()))
         return self
 
     def set_color_by_rgb_func(
         self,
-        func: Callable[[Vect3], Vect3],
+        func: Callable[[Vect3Array], Vect3Array],
         opacity: float = 1,
         recurse: bool = True
     ) -> Self:
@@ -1344,8 +1340,9 @@ class Mobject(object):
         Func should take in a point in R3 and output an rgb value
         """
         for mob in self.get_family(recurse):
-            rgba_array = [[*func(point), opacity] for point in mob.get_points()]
-            mob.set_rgba_array(rgba_array)
+            points = mob.get_points()
+            opacity = np.ones((points.shape[0], 1)) * opacity
+            mob.set_rgba_array(np.hstack((func(points), opacity)))
         return self
 
     @affects_family_data
diff --git a/manimlib/mobject/number_line.py b/manimlib/mobject/number_line.py
index 9f9bc4d0..7f27f6a9 100644
--- a/manimlib/mobject/number_line.py
+++ b/manimlib/mobject/number_line.py
@@ -182,9 +182,13 @@ class NumberLine(Line):
         if x < 0 and direction[0] == 0:
             # Align without the minus sign
             num_mob.shift(num_mob[0].get_width() * LEFT / 2)
-        if x == unit and unit_tex:
+        if abs(x) == unit and unit_tex:
             center = num_mob.get_center()
-            num_mob.remove(num_mob[0])
+            if x > 0:
+                num_mob.remove(num_mob[0])
+            else:
+                num_mob.remove(num_mob[1])
+                num_mob[0].next_to(num_mob[1], LEFT, buff=num_mob[0].get_width() / 4)
             num_mob.move_to(center)
         return num_mob