Determine label color based on lowercase name

app/helpers/labels_helper.rb

@@ -12,7 +12,7 @@ module LabelsHelper
   def label_css_class(name)
     klass = Gitlab::IssuesLabels
 
-    case name
+    case name.downcase
     when *klass.warning_labels
       'label-warning'
     when *klass.neutral_labels

spec/helpers/labels_helper_spec.rb

+require 'spec_helper'
+
+describe LabelsHelper do
+  describe '#label_css_class' do
+    it 'returns label-danger when given Bug as param' do
+      expect(label_css_class('bug')).to eq('label-danger')
+    end
+
+    it 'returns label-danger when given Bug as param' do
+      expect(label_css_class('Bug')).to eq('label-danger')
+    end
+  end
+end