Recommendations for Identifying Corelle Patterns 

This website isn't geared to identifying Corelle patterns.  There are hundreds of patterns, and other sites have already done a considerable amount of work in creating excellent Corelle identification pages.  The following suggestions are the most complete on-line resources available for identifying patterns.
My top recommendation is the retired Corelle identification section of Microwave Cooking for One.  It has excellent pictures in a semi gallery format, and the site is frequently updated when new patterns appear.  Opal Pyrex patterns and Corning Ware patterns are also featured there.  And take the opportunity to check out the cookbook on offer there as well.  I have a copy and I refer to it frequently!  It is an excellent and detailed guide for successful microwave cooking.
Replacements Ltd. has a large photo gallery, but the picture quality can be inconsistent, and not all patterns are named correctly.  Some familiar patterns are listed as unknowns with substitute names like COR01, etc., but those that have a real name are often correct.  Products are mainly categorized by manufacturer's name only, so Corelle, Centura, Comcor and Crown Corning porcelain & stoneware are lumped together under "Corning".  Pyrex is also on that site, but the brand is treated as a separate entity for some reason, and many of the pattern names provided are incorrect.
If you're wondering whether a certain piece was made in a particular pattern, check through the lists of pieces in stock as well as those that are sold out at the bottom of the page.   If the item is on that page then it almost certainly exists, because they either have it for sale now or they have sold one in the past.  But the reverse may not be true.  Your item might exist, but if they have never had one in stock, they have no reason to add it to the list.
Related Articles:

Corelle Pattern Profiles, Alphabetical
Extra Photos: Comcor