Use Hex Code to Mix Colors please help

Tell us what’s happening:

Your code so far

<!--<style>
  .red-text {
    color: black;
  }
  .green-text {
    color: black;
  }
  .dodger-blue-text {
    color: black;
  }
  .orange-text {
    color: black;
  }
</style>-->

<style>
  .FF0000 {
    color: #FF0000;
  }
  .00FF00
  {
    color: #00FF00;
  }
  .2998E4{
    color: #2998E4;
  }
  .FFA500
  {
    
    .color:#FFA500;
  }
</style>

<h1 class="FF0000"> <!--"red-text"--> I am red!</h1>

<h1 class="00FF00"> <!--"green-text"--> I am green!</h1>

<h1 class="2998E4"> <!--"dodger-blue-text"--> I am dodger blue!</h1>

<h1 class="FFA500"> <!--"orange-text"--> I am orange!</h1>

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.98 Safari/537.36.

Link to the challenge:
https://www.freecodecamp.org/challenges/use-hex-code-to-mix-colors

What is appertaining here?

.FFA500
  {
     .color:#FFA500;
  }