Refactor ColorAnnotator default color and enhance documentation

Changed the default color for ColorAnnotator from RGB(0,0,0) to the black color constant. Also improved the clarity of initialisation comment (color used for region painting, not replacing). A wrong variable name 'blur_annotator' is also rectified to 'color_annotator'.

docs/annotators.md

@@ -229,6 +229,27 @@
 
     </div>
 
+=== "Color"
+
+    ```python
+    >>> import supervision as sv
+
+    >>> image = ...
+    >>> detections = sv.Detections(...)
+
+    >>> color_annotator = sv.ColorAnnotator()
+    >>> annotated_frame = color_annotator.annotate(
+    ...     scene=image.copy(),
+    ...     detections=detections
+    ... )
+    ```
+
+    <div class="result" markdown>
+
+    ![color-annotator-example](https://media.roboflow.com/supervision-annotator-examples/color-annotator-example-purple.png){ align=center width="800" }
+
+    </div>
+
 === "Trace"
 
     ```python
@@ -337,6 +358,10 @@
 
 :::supervision.annotators.core.BlurAnnotator
 
+## ColorAnnotator
+
+:::supervision.annotators.core.ColorAnnotator
+
 ## TraceAnnotator
 
 :::supervision.annotators.core.TraceAnnotator

supervision/annotators/core.py

@@ -1205,10 +1205,10 @@ class ColorAnnotator(BaseAnnotator):
     using provided detections.
     """
 
-    def __init__(self, color: Color = Color(r=0, g=0, b=0)):
+    def __init__(self, color: Color = Color.black()):
         """
         Args:
-            color (Color): The color to replace the regions with.
+            color (Color): The color to paint the regions with.
         """
         self.color: Color = color
 
@@ -1235,7 +1235,7 @@ def annotate(
             >>> image = ...
             >>> detections = sv.Detections(...)
 
-            >>> blur_annotator = sv.ColorAnnotator()
+            >>> color_annotator = sv.ColorAnnotator()
             >>> annotated_frame = color_annotator.annotate(
             ...     scene=image.copy(),
             ...     detections=detections