Text widget – button font colour problem

Interesting problem – I have a button which appears twice on http://kingdomwaytrust.org/winter-night-shelter/ for Volunteers to login. In the main page it appears fine, but in the sidebar I have exactly the same code in a text widget and the font is grey instead of white. I’ve tried making buttons with a number of different plugins and all do exactly the same thing – the font colour changes as soon as it’s placed in the sidebar text widget.

The current version uses the All In One Button plugin so code in the widget is:

[aio_button align=”center” animation=”none” color=”green” size=”medium” icon=”none” text=”Volunteer Login” target=”_blank” url=”http://kingdomwaytrust.org/wnsadmin/login.php”%5D

[maxbutton id=”1″]

The Admin Button uses maxbutton and the font is fine, however, the free version of maxbuttons do not shrink nicely when the screen size changes, which is why I’m searching for a better alternative. May need to make my own as a graphic but still would like to know why the above happens!

Thanks for any help.