You can easily add gradient text:

  1. Click the Text tab from the side panel
  2. Add text to the canvas editor. 
  3. In the main navigation menu, click on the gradient text icon. 
  4. Apply your gradient effect to the text as necessary.  

To remove the gradient text effect, simply change the color of the text to a solid color using the normal text color changer, this will reset the text into standard color scheme.