showy in a tasteless or vulgar way
gaudy - flashy
Something 'gaudy' is considered overly flashy and tends to involve offensively bright and ill-fitting colours, along with excessive ornamentation and tasteless extravagance. The overall effect is something tacky that inspires disdain and disapproval, unless done deliberately for effect in an ironic or knowing way.
I would never trust a salesperson that wears that much gaudy jewelry. It does not inspire trust.
The hotel was decorated gaudily and seemed designed to attract a particular class of clientele.
I want the design to be something colourful and kitsch, so the gaudier the better.