CSS Names is a collection of small modules that make it possible to add theming to items that were previously difficult to target with css selectors. Most of these modules just add additional class names to a particular HTML element, with the class name based on the element's content or position within the parent structure.
The No Colons module allows you to remove colons from form labels and other types of label text. There are two modes of operation: Remove all colons -or- Remove colons only if label text ends in punctuation (such as a question mark).