Itamar Tzadok

Then it might be that the 'Trust submitted content' capability is not allowed for the role you have unless you are an administrator to whom it should be allowed by default.

If that too doesn't work I have a workaround for you which may work at least on the main page. Each block is uniquely identified and the block title of a block an h2 tag. So you can add local css definitions on the page for setting the color (and other styles) of particular titles by means of the #block-id h2 css definition.

How to do it:

1. Create an Html block and place it (or leave it) in the bottom right corner of the page.
2. Edit the block and in text mode add the following lines:
   <div id="myStyles"></div>
   <script type="text/javascript">
   var styleHtml;
   styleHtml+='<style>';
   styleHtml+='#inst------ h2{color:red}';
   styleHtml+='</style>';
   if(document.getElementById("myStyles")){
   document.getElementById("myStyles").innerHTML=styleHtml;
   }
   </script>
3. Substitute ------ for the actual instance id of the designated block. You can get this number by simply hovering over the block edit link (in editing mode) and observing the url which should specify the instanceid number as a parameter.
4. Save and close.
5. The designated block title should appear in the new color as soon as the page is refreshed.

You may observe that the definitions block appears on the page although in a minimal way. We can make it completely invisible and I actually wrote in details how, but that part was truncated from this message for some reason. I'll write it again if you're interested. Let me know.

Have you tried

<span style="color:red;">Block title</span>

?

And the list view with the popup popped up with the Moodle xml:

An entry in the single view:

The html file for the popup.