diff --git a/README.md b/README.md
index f13ae26..065af82 100644
--- a/README.md
+++ b/README.md
@@ -266,3 +266,22 @@ cmake and g++ themes:
 You then can use the `cm` alias as a prefix to your build command,
 for example: `cm make test`
 
+
+### Themes
+
+You can easily add your own theme to colout.
+A theme is basically a module with a function named `theme` that take the configuration context as an argument and
+return back the (modified) context and a list of triplets.
+Each triplet figures the same arguments than those of the command line interface.
+
+    def theme(context):
+        return context,[ [regexp, colors, styles] ]
+
+With the context dictionary at hand, you have access to the internal configuration of colout, you can thus change colormaps for
+special keywords, the scale, even the available colors, styles or themes.
+
+See the cmake theme for how to modify an existing colormap if (and only if) the user didn't ask for an
+alternative one.
+See the ninja theme for how to extend an existing theme with more regexps and a different configuration. 
+See the gcc theme for an example of how to use the localization of existing softwares to build translated regexp.
+
diff --git a/colout/colout.py b/colout/colout.py
index 41346c6..94b06ba 100755
--- a/colout/colout.py
+++ b/colout/colout.py
@@ -68,6 +68,8 @@ context["colormaps"]["Hash"] = context["colormaps"]["Rainbow"]
 context["colormaps"]["default"] = context["colormaps"]["spectrum"]
 context["colormaps"]["Default"] = context["colormaps"]["Spectrum"]
 
+context["user_defined_colormaps"] = False
+
 context["colormap_idx"] = 0
 
 context["scale"] = (0,100)
@@ -100,6 +102,7 @@ def set_special_colormaps( cmap ):
     context["colormaps"]["Default"] = cmap
     context["colormaps"]["random"] = cmap
     context["colormaps"]["Random"] = cmap
+    context["user_defined_colormaps"] = True
     logging.debug("user-defined special colormap: %s" % ",".join([str(i) for i in cmap]) )
 
 
diff --git a/colout/colout_cmake.py b/colout/colout_cmake.py
index cca396f..68ff06e 100644
--- a/colout/colout_cmake.py
+++ b/colout/colout_cmake.py
@@ -8,9 +8,11 @@ def theme(context):
     #  actions taking an unknown time
     untimed="blue"
 
-    # A palette that goes: purple, orange, white
-    percs = [45, 39, 33, 27, 21, 57, 63, 62, 98, 97, 133, 132, 138, 173, 172, 208, 214, 220, 226, 228, 229, 230, 231, 255]
-    context["colormaps"]["Scale"] = percs
+    # If the user do not ask for his own colormap
+    if not context["user_defined_colormaps"]:
+        # A palette that goes: purple, orange, white
+        percs = [45, 39, 33, 27, 21, 57, 63, 62, 98, 97, 133, 132, 138, 173, 172, 208, 214, 220, 226, 228, 229, 230, 231, 255]
+        context["colormaps"]["Scale"] = percs
 
     return context,[
         # Configure...
@@ -31,9 +33,6 @@ def theme(context):
         # Link (make)
         [ "^(Linking .* )(library|executable) (.*/)*(.+(\.[aso]+)*)$",
           untimed, "normal,normal,bold" ],
-        # Link (ninja)
-        [ "^\[[0-9/]+\]\s?(Linking .* )(library|executable) (.*/)*(.+(\.[aso]+)*)$",
-          untimed, "normal,normal,bold" ],
         # [percent] Built
         [ "^\[\s*[0-9/]+%?\]\s(Built target)(\s.*)$",
           performed, "normal,bold" ],
@@ -47,7 +46,5 @@ def theme(context):
         [ "make\[[0-9]+\].*", "yellow"],
         [ "(make: \*\*\* \[.+\] )(.* [0-9]+)", "red", "normal,bold"],
         # progress percentage (make)
-        [ "^(\[\s*[0-9]+%\])","Scale" ],
-        # progress percentage (ninja)
-        [ "^(\[[0-9]+/[0-9]+\])","Scale" ]
+        [ "^(\[\s*[0-9]+%\])","Scale" ]
     ]
diff --git a/colout/colout_ninja.py b/colout/colout_ninja.py
new file mode 100644
index 0000000..1d416c9
--- /dev/null
+++ b/colout/colout_ninja.py
@@ -0,0 +1,19 @@
+
+import colout_cmake
+
+def theme(context):
+    # Ninja theme
+
+    # Inherit from the CMake theme
+    context,th = colout_cmake.theme(context)
+
+    # Because Ninja note progress as a fraction, we do not want the scale of a percentage
+    context["scale"] = (0,1)
+
+    # Link (ninja)
+    th.append( [ "^\[[0-9/]+\]\s?(Linking .* )(library|executable) (.*/)*(.+(\.[aso]+)*)$",
+          "blue", "normal,normal,bold" ] )
+    # progress percentage (ninja)
+    th.append( [ "^(\[[0-9]+/[0-9]+\])","Scale" ] )
+
+    return context,th