but I looked it up and was proven wrong:
"There are two schools of thought on this word, in addition to one erroneous explanation. First, it is thought that gaudy comes from a color term from Middle English, gaudy-green, which itself originated because the plant which produced the dye was once known as weld, and weld, when borrowed into Old French, became gaude - hence English gaudy-green. It is said that gaudy soon lost its specific color connotations and came to refer to anything 'bright.'
The second explanation is that the term comes from English gaud 'joke, plaything.' That word was adapted from Old French gaudir 'rejoice,' a descendant of Latin gaudere 'delight in' (from which English gets joy). The word gaudy still serves as a noun in English which means "rejoicing, joy, merrymaking; a festival", though it has probably gained obsolete status these days.
The erroneous explanation is that the term comes from the name of the Spanish architect Antonio Gaudi (1852-1926), whose architecture some believe today is gaudy. This suggestion can be discounted by virtue of the fact that gaudy dates back to the 16th century."