Add a gif image for readme

README.md

@@ -16,7 +16,7 @@ First demo is one of the sequence labeling tasks, named-entity recognition. You
 
 Second demo is one of the text classification tasks, topic classification. Since there may be more than one category, you can annotate multi-labels.
 
-![Text Classification](http://via.placeholder.com/600x400)
+![Text Classification](./docs/text_classification.gif)
 
 ### Sequence to sequence
 

app/server/templates/annotation/document_classification.html

@@ -26,7 +26,8 @@
         <div class="field is-grouped is-grouped-multiline">
             <div class="control" v-for="(annotation, index) in items[cur].labels">
                 <div class="tags has-addons">
-                    <span class="tag is-dark">
+                    <span class="tag"
+                          v-bind:style="{ color: annotation.label.text_color, backgroundColor: annotation.label.background_color }">
                         [[ annotation.label.text ]]
                         <button class="delete is-small" v-on:click="deleteLabel(index)"></button>
                     </span>