How to create SpanIndicator to simulate URL link

I have a case where I cannot use a language file, but would like to create a SpanIndicator that will display some text as a URL link. I want the text to be blue and be underlined. My first thought was to simply create a SpanIndicator using IndicatorMarks.StyleAssignment, and then provide a HighlightingStyle that includes the underline attribute. This works, however if my link text contains spaces, the spaces are not underlined and it ends up looking like several different links.

My next attempt was to set the IndicatorMarks.Adornments, and just paint the underline myself. The problem with this approach is that it ignores the style and my text is black instead of blue. Is there a way for me to include both IndicatorMarks types?