override class default color

[Dave]

I have a button based on the tag pill sytle:

<$list filter="[is[current]has[due]]">

  <$button message="tm-delete-tiddler"  tooltip="delete tiddler" class="tc-tag-label tc-btn-invisible {background-color:red;}">

    delete

  </$button>

</$list>

But I want it to be a different color than the default color that comes with the "tc-tag-label" class.

What I added in there "{background-color:red;}" doesn't work. 

A) how do I do this?

and 

B) is there a place I could have looked this up myself (other than this forum?)

I got the idea from here:

https://groups.google.com/forum/#!searchin/TiddlyWiki/override$20class$20color|sort:relevance/tiddlywiki/WFyuhNTXCyQ/SBT9SvimCwAJ

but I didn't understand the context

[S. S.]

There are probably other ways to do it, but this should work:

<span style=background-color:red; class=tc-tag-label>

<$list filter="[is[current]has[due]]">

  <$button message="tm-delete-tiddler"  tooltip="delete tiddler" class=" tc-btn-invisible">
    delete
  </$button>
</$list>
</span>

I also struggled to find this method some months ago. Unfortunately I forgot where I got the hints from.

[Dave]

 Thank you -  That works great!