diff --git a/colour_visuals/axes.py b/colour_visuals/axes.py
index d5c7d0f..46259bc 100644
--- a/colour_visuals/axes.py
+++ b/colour_visuals/axes.py
@@ -3,7 +3,7 @@
 Axes Visuals
 ============
 
-Defines the axes visuals:
+Define the axes visuals:
 
 -   :class:`colour_visuals.VisualAxes`
 """
diff --git a/colour_visuals/common.py b/colour_visuals/common.py
index a3b0605..37e58a4 100644
--- a/colour_visuals/common.py
+++ b/colour_visuals/common.py
@@ -2,7 +2,7 @@
 Common Utilities
 ================
 
-Defines the common utilities objects that don't fall in any specific category.
+Define the common utilities objects that don't fall in any specific category.
 """
 
 from __future__ import annotations
diff --git a/colour_visuals/daylight_locus.py b/colour_visuals/daylight_locus.py
index d0c991e..21f904b 100644
--- a/colour_visuals/daylight_locus.py
+++ b/colour_visuals/daylight_locus.py
@@ -3,7 +3,7 @@
 Daylight Locus Visuals
 =======================
 
-Defines the *Daylight Locus* visuals:
+Define the *Daylight Locus* visuals:
 
 -   :class:`colour_visuals.VisualDaylightLocus`
 """
diff --git a/colour_visuals/diagrams.py b/colour_visuals/diagrams.py
index 150b835..d11d620 100644
--- a/colour_visuals/diagrams.py
+++ b/colour_visuals/diagrams.py
@@ -3,7 +3,7 @@
 Chromaticity Diagram Visuals
 ============================
 
-Defines the *Chromaticity Diagram* visuals:
+Define the *Chromaticity Diagram* visuals:
 
 -   :class:`colour_visuals.VisualSpectralLocus2D`
 -   :class:`colour_visuals.VisualSpectralLocus3D`
diff --git a/colour_visuals/grid.py b/colour_visuals/grid.py
index d6f6ec6..3f1da13 100644
--- a/colour_visuals/grid.py
+++ b/colour_visuals/grid.py
@@ -3,7 +3,7 @@
 Grid Visuals
 ============
 
-Defines the grid visuals:
+Define the grid visuals:
 
 -   :class:`colour_visuals.VisualGrid`
 """
diff --git a/colour_visuals/patterns.py b/colour_visuals/patterns.py
index f9921e5..7cc36fa 100644
--- a/colour_visuals/patterns.py
+++ b/colour_visuals/patterns.py
@@ -2,7 +2,7 @@
 Pattern Generators
 ==================
 
-Defines various pattern generators:
+Define various pattern generators:
 
 -   :func:`colour_visuals.pattern_hue_swatches`
 -   :func:`colour_visuals.pattern_hue_stripes`
diff --git a/colour_visuals/planckian_locus.py b/colour_visuals/planckian_locus.py
index 9ae675b..a2ec9a2 100644
--- a/colour_visuals/planckian_locus.py
+++ b/colour_visuals/planckian_locus.py
@@ -3,7 +3,7 @@
 Planckian Locus Visuals
 =======================
 
-Defines the *Planckian Locus* visuals:
+Define the *Planckian Locus* visuals:
 
 -   :class:`colour_visuals.VisualPlanckianLocus`
 """
diff --git a/colour_visuals/pointer_gamut.py b/colour_visuals/pointer_gamut.py
index 21b4d90..47ed1a3 100644
--- a/colour_visuals/pointer_gamut.py
+++ b/colour_visuals/pointer_gamut.py
@@ -3,7 +3,7 @@
 Pointer Gamut Visuals
 =====================
 
-Defines the *Pointer's Gamut* visuals:
+Define the *Pointer's Gamut* visuals:
 
 -   :class:`colour_visuals.VisualPointerGamut2D`
 """
diff --git a/colour_visuals/rgb_colourspace.py b/colour_visuals/rgb_colourspace.py
index 9704cde..538f1e0 100644
--- a/colour_visuals/rgb_colourspace.py
+++ b/colour_visuals/rgb_colourspace.py
@@ -3,7 +3,7 @@
 RGB Colourspace Visuals
 =======================
 
-Defines the *RGB colourspace* visuals:
+Define the *RGB colourspace* visuals:
 
 -   :class:`colour_visuals.VisualRGBColourspace2D`
 -   :class:`colour_visuals.VisualRGBColourspace3D`
diff --git a/colour_visuals/rgb_scatter.py b/colour_visuals/rgb_scatter.py
index 5cbf42e..1d7f83d 100644
--- a/colour_visuals/rgb_scatter.py
+++ b/colour_visuals/rgb_scatter.py
@@ -3,7 +3,7 @@
 RGB Scatter Visuals
 ===================
 
-Defines the *RGB* scatter visuals:
+Define the *RGB* scatter visuals:
 
 -   :class:`colour_visuals.VisualRGBScatter3D`
 """
diff --git a/colour_visuals/rosch_macadam.py b/colour_visuals/rosch_macadam.py
index 473f727..3cd2ab5 100644
--- a/colour_visuals/rosch_macadam.py
+++ b/colour_visuals/rosch_macadam.py
@@ -3,7 +3,7 @@
 Rösch-MacAdam Visuals
 =====================
 
-Defines the *Rösch-MacAdam* visuals:
+Define the *Rösch-MacAdam* visuals:
 
 -   :class:`colour_visuals.VisualRoschMacAdam`
 """
diff --git a/colour_visuals/visual.py b/colour_visuals/visual.py
index 66fdcbc..afc8624 100644
--- a/colour_visuals/visual.py
+++ b/colour_visuals/visual.py
@@ -2,7 +2,7 @@
 Visual Utilities
 ================
 
-Defines the visual utilities.
+Define the visual utilities.
 """
 
 from __future__ import annotations