title: Changes in Apache SuperSet .less templates are not being applied to interface after build
body: <p>I'm currently running Apache Superset which is working very well.</p>
  <p>However, I've now received a requirement to make a few structural changes to the CSS layout and formatting of the Superset interface. Making changes to the dashboard CSS templates and config.py won't be sufficient. So what I would like to achieve is to make changes to the superset .less templates and have chose changes applied to the interface. However, so far I've not been able to successfully making any changes to the interface by changing the .less templates.</p>
  <p>What I've tried to far is to:</p>
  <ol>
  <li>Follow all the instructions to build my Apache Superset from source using the instructions here: <a href="https://github.com/apache/superset/blob/master/CONTRIBUTING.md#setup-local-environment-for-development" rel="nofollow noreferrer">https://github.com/apache/superset/blob/master/CONTRIBUTING.md#setup-local-environment-for-development</a></li>
  <li>Make changes to the .less templates as described here: <a href="https://debaatobiee.wordpress.com/2019/08/04/customizing-apache-superset-ui-config-theme-changes/" rel="nofollow noreferrer">https://debaatobiee.wordpress.com/2019/08/04/customizing-apache-superset-ui-config-theme-changes/</a></li>
  </ol>
  <p>However, after making changes to the .less templates, and rebuilding using &quot;npm run build&quot; and &quot;npm run dev-server&quot; in directory superset-frontend, it seems that those changes are not being applied.</p>
  <p>Am I doing any steps incorrectly? I'm using a aws t3.large machine with Ubuntu Server 20.04 LTS (HVM) x86 and I run the following commands from machine creation:</p>
  <pre><code>sudo apt update
  sudo apt upgrade
  sudo apt-get install build-essential libssl-dev libffi-dev python3-dev python3-pip libsasl2-dev libldap2-dev libmysqlclient-dev python3.8-venv
  git clone https://github.com/apache/superset.git
  cd superset
  python3 -m venv venv  
  . venv/bin/activate
  pip install -r requirements/development.txt
  pip install pymssql
  pip install -e .
  superset db upgrade
  superset fab create-admin
  superset init
  curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.37.0/install.sh | bash
  source ~/.nvm/nvm.sh
  cd superset-frontend
  nvm install --lts
  nvm use --lts
  npm ci
  </code></pre>
  <p>I edit the file ~/superset/superset-frontend/src/assets/stylesheets/less/variables.less as follows:</p>
  <p>Replace <strong>@primary-color: #20a7c9</strong> with <strong>@primary-color: #00ff00</strong></p>
  <p>Now in one command prompt I run the following command:</p>
  <pre><code>FLASK_ENV=development superset run -p 8088 -h 0.0.0.0 --with-threads --reload --debugger
  </code></pre>
  <p>And in another command prompt I run the following:</p>
  <pre><code>npm run build
  npm run dev-server
  </code></pre>
  <p>I can successfully connect to the page on port 9000. However, even after ctrl+f5 the css never seems to change according to the changes I made in the .less templates. In this example I would have expected the color to have changed (no more #20a7c9 in the css, but #00ff00 instead).</p>
  <p>What am I doing incorrectly in my approach? Or is there an easier way to do what I'm trying to do (make site-wide LESS/CSS changes)? I've tried using Docker but I wasn't successful in making that work.</p>