Can’t change color for WordPress link

I’m working on my site, and want to change the color of the WordPress link in the footer. I know from this page ( https://www.tamba2.org.uk/graphicalcss/footer/index.html ) I add:
.credit a {
color: #00ff00;
}
I want it white so I changed it to #ffffff. The only problem is that nothing changes. It is still the same color as before.
I’ve changed the settings under .credit a:link, a:hover, etc to reflect my colors and they change. I tried adding an a:visitor to this list, but it didn’t work. The only way I could get the link to change was to alter the color under the general a:visited section at the top of the file.
What am I doing wrong? The site is https://culturecritic.com/bbtest/index.php is anyone wants to look.