try and force the style using the !important after the format, before the semicolon:
.entry-meta a,
.entry-utility a {
color: #888!important;
}
.entry-meta a:hover,
.entry-utility a:hover {
color: #EC74AF!important;
}
not ideal, but it seems to work.
---
actually, this style from marketplace.css (http://parisinpink.com/blog/wp-content/plugins/wp-e-commerce/themes/marketplace/marketplace.css?ver=3.7.59) is overwriting your selection:
.category a{
color:#0066CC;
}
the interference is triggered by the body_class .category which is added by twentyten to the body tag of category archives.
---
btw:
twenty ten as the default theme of wp3 will be overwritten with the next upgrade of your wordpress version - all your modification will be lost.
strongly consider to create a child theme: http://codex.wordpress.org/Child_Themes
and keep making regular backup copies of your theme files