<?php the_content( __( 'Continue reading <span class="meta-nav">&rarr;</span>', 'twentyten' ) ); ?>

.meta-nav {
    color: red;
    font-size: 3em;
    /* any styling you want! */
}

.meta-nav {
    /* Your styles here */
}

.meta-nav {
color:red !important;
font-size:3em !important;
}