It is not possible to provide antonyms for the phrase "blue plate," as it is not a single word but rather a phrase that refers to a type of dishware or a diner-style meal served on a specific type of plate. However, some possible antonyms for the word "blue" could be colors such as red, green, or yellow, which are complementary colors and are often used in contrast with blue. As for plate, antonyms such as cup, bowl, or saucer could be used, depending on the context of the sentence.