hyperlinks within buttons

hi, I have some contextual links within some survey questions. The questions are styled to be buttons.
Problem is when selecting the button the blue hyperlink is barely readable against the dark button colour.
I would like to change the hyperlink text to white when the button is checked. Changing the hover or active on the link does not change the button styling.

.Skin label.MultipleAnswer.q-checked, .Skin label.SingleAnswer.q-checked {
  background: #003b3f;
  border-color: #000;
  color: fff;
}

a:link {
 color: blue;
}
/* visited link*/
a:visited {
 color: blue;
}
/* mouse over link */
a:hover {
 color: blue;
}
/* selected link */
a:active {
 color: blue;
}