diff --git a/taiga/projects/tagging/services.py b/taiga/projects/tagging/services.py
index 4e7fe1f7..e281eaa5 100644
--- a/taiga/projects/tagging/services.py
+++ b/taiga/projects/tagging/services.py
@@ -24,12 +24,12 @@ def tag_exist_for_project_elements(project, tag):
 
 
 def create_tags(project, new_tags_colors):
-    project.tags_colors += [[k, v] for k, v in new_tags_colors.items()]
+    project.tags_colors += [[k.lower(), v] for k, v in new_tags_colors.items()]
     project.save(update_fields=["tags_colors"])
 
 
 def create_tag(project, tag, color):
-    project.tags_colors.append([tag, color])
+    project.tags_colors.append([tag.lower(), color])
     project.save(update_fields=["tags_colors"])
 
 
diff --git a/taiga/projects/tagging/validators.py b/taiga/projects/tagging/validators.py
index ea0c32c8..4070045d 100644
--- a/taiga/projects/tagging/validators.py
+++ b/taiga/projects/tagging/validators.py
@@ -50,7 +50,7 @@ class CreateTagValidator(ProjectTagValidator):
 
     def validate_color(self, attrs, source):
         color = attrs.get(source, None)
-        if color is not None and not re.match('^\#([a-fA-F0-9]{6}|[a-fA-F0-9]{3})$', color):
+        if color and not re.match('^\#([a-fA-F0-9]{6}|[a-fA-F0-9]{3})$', color):
             raise ValidationError(_("The color is not a valid HEX color."))
 
         return attrs