Customise 'Complete Your Order' Button in Abandoned Cart Recovery Email

Hi, 

In the Abandoned Cart Recovery email, there is a Complete Your Order button. I can't see where I can customise this button (just want to change the colour to match my other emails)?

Also, is there a way to get rid of the underline that automatically shows under the title of the email (due to this being a link to the website, but I'd like it removed if possible)?

I shifted the Title to the body of the email and styled it within a DIV block to make it look like my Title

<div style="
color: #1E1E1E; 
font-family:Helvetica; 
font-size:170%; 
font-weight: bold">

  We've Saved Your Cart For You!

</div>

Or, shove it in something like this within the email if you need a link adding to somewhere:

<a style="
          color: #1E1E1E; 
          font-family:Helvetica; 
          text-decoration: none; 
          font-size:150%; 
          font-weight: bold" 
   href="{website.baseUrl}">LINK TEXT</a>

As for buttons, I have no idea how to customise them unfortunately. You can copy the HTML that creates the button, add it to the body of the email and alter the style to match your site, but you can't also remove the button that is there by default (so you can only create two buttons, which isn't great...)