Hello Craig,
To handle the user click on the hyperlink you need to attach to HyperLinkClick event of NRichTextLable.Item property:
nRichTextLabel1.Item.HyperLinkClick += Item_HyperLinkClick;
To change the color of the hyperlink you need to surround the anchor tag with font tag with desired color:
nRichTextLabel1.Text = "<font color=\'red\'><a href=\"url\">my link</a></font>";