Make colour injecting not the default and put in better safegaurds around injecting the cmap

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "makegraph"
-version = "0.2.0"
+version = "0.2.1"
 description = "A custom python Matplotlib wrapper"
 readme = "README.md"
 authors = [
@@ -13,4 +13,4 @@ dependencies = [
 
 [build-system]
 requires = ["uv_build>=0.10.2,<0.11.0"]
-build-backend = "uv_build"
+build-backend = "uv_build"

src/makegraph/__init__.py

@@ -2,7 +2,7 @@ from .colours import ColourValue, ColourContainer
 from .uq_colours import UQ_COLOURS_DICT, UQ_COLOURS, add_colours_to_mpl
 from .makegraph import makeGraph, pltKeyClose
 
-__version__ = "0.2.0"
+__version__ = "0.2.1"
 
 __all__ = [
     "makeGraph", "pltKeyClose",

src/makegraph/uq_colours.py

@@ -18,8 +18,7 @@ if _MG_INJECT_MPL_COLOURS_ENVIRON_VAR in os.environ:
     except ValueError:
         INJECT_COLOURS = False
 else:
-    # Default to always injecting colours on load
-    INJECT_COLOURS = True
+    INJECT_COLOURS = False
 
 # Define the UQ Colours
 UQ_COLOURS_DICT = {
@@ -111,7 +110,11 @@ for i, c in enumerate(uq_colour_map_grad):
     uq_colour_dict["blue"].append(  (offset, c[2], c[2]) )
 
 #Define & register the colour map itself
-uq_cmap = mpl_colors.LinearSegmentedColormap('uq', segmentdata=uq_colour_dict)  # ty:ignore[invalid-argument-type]
+UQ_CMAP_NAME = "uq"
+uq_cmap = mpl_colors.LinearSegmentedColormap(
+    name=UQ_CMAP_NAME, 
+    segmentdata=uq_colour_dict # ty:ignore[invalid-argument-type]
+)
 
 # Wrap all MPL calls in a function
 def add_colours_to_mpl(update_cycler: bool = True, once_only: bool = False):
@@ -129,7 +132,8 @@ def add_colours_to_mpl(update_cycler: bool = True, once_only: bool = False):
         plt.rc('axes', prop_cycle=uq_colour_cycler)
 
     # Add the colour map to MPL
-    matplotlib.colormaps.register(uq_cmap)
+    if UQ_CMAP_NAME not in matplotlib.colormaps:
+        matplotlib.colormaps.register(uq_cmap)
 
     # Set the colour map - Not a very good default so not doing that
     #plt.set_cmap("uq")