My company recently rebranded and one of the design elements put in place in our emails was purple CTA buttons to match the purple that is now the prominent color in our new brand. The purple buttons have white text. The issue we are having is that when users click on the text in the email the text becomes purple and the button looks like a solid block of color without any text.

This is the coding for the button:

<table border="0" cellpadding="10" cellspacing="0" class="wtw-register-btn" style="background-color: #702082;color: #000;font-family: Arial;font-size: 18px;font-weight: normal;line-height: 120%;text-align: left;text-transform: uppercase;text-decoration: none;border-collapse: separate !important;" width="100%">
                                                            <td style="border-collapse: collapse;">
                                                            <h5 style="color: #000;display: block;font-family: Arial;font-size: 15px;mso-line-height-rule: exactly;line-height: 140%;margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;text-align: center;"><a href="" name="event_tool_3" style="color: #fff;font-weight: bold;text-decoration: none;" xt="SPCLICK">
                                                            Register for event</a></h5>

I have tried to implement the following as a solution:

Add a class to the register button where the h5 is –

<h5 class=”wtw-register-button”><a href=”#”>Register for Event</a></h5>

And add this css:

.wtw-register-button > a:visited {color: #fff;}

However, it has not fixed the issue on the tests I have run.

Is there another way to change the "visited color" that renders consistently across email platforms?