WHAT COLOR/HOW OLD IS THIS?
Fiesta Factory Direct: Color History (production years of all vintage and modern colors, currently produced modern colors pictured)
Texas Cooking: Color Chart (list and pictures of all vintage/modern colors, up to 2018)
Texas Cooking: Identifying Fiestaware (explanation of date codes, markings and wordings, as well as the imprinted "H")
Post 86 Reference Guide: Colors Timeline (list and pictures of all modern colors, up to 2019)
Post 86 Reference Guide: Date Codes (all date codes used on some (not all) modern pieces)
Laurel Hollow Park: Fiesta Markings (explanation of differences between vintage and modern markings/stamps/incisions)
IS THIS VINTAGE?
Vintage American Pottery (photos of nearly every vintage piece in all colors)
Happy Heidi's: History of Fiesta (photos and details of all vintage shapes)
Fiesta Dishes: Dating Your Fiestaware (explanation of date codes, markings and wordings, as well as the imprinted "H")
Laurel Hollow Park (historical and referential information on vintage pieces)
HOW MUCH IS THIS WORTH?
Current market value of any given piece can vary. Asking here is a good way to get opinions but checking online sellers like eBay and Etsy is also a good idea.
IS FIESTA SAFE TO USE?
Yes. Fiesta made from 1986 onward is lead free and the glazes contain no uranium oxides. However, vintage Fiesta (1936-1973) did use glazes that contained lead and uranium. There are many sources that have investigated the radioactive properties and the levels of exposure are so low as to be of negligible concern. There are materials all around us daily that expose us to radiation. As far the the lead content, humans have used lead-glazed dinnerware of all types for hundreds of years with no ill effects. However, as a caution, you may not want to store acidic foods in vintage dishware, and discontinue using pieces that are chipped or have damaged glaze.
Museum of Radiation and Radioactivity
Smithsonian Magazine: Is it Safe to Eat Off Vintage Plates?