Steps to reproduce the issue

Add the Twitter Timeline Widget to a sidebar and enter jetpack in the field and change nothing else:

Check the widget on the front end of the site:

Go back to the widget settings and change the link color to anything else:

Check the front end again and nothing has changed.

It appears that the link color no longer works. Also, setting the Border Color also has undesired results:

I checked to see if it was tied to whatever colors are set on the Twitter page, but that has no relevance to these settings.

Reported in 2722461-zen