Attire for a semi-formal event

I'm thinking of ditching the suit jacket for this event on saturday, and just going with either a navy blue vest and pants, light purple shirt, and tie, or a red shirt, black vest and pants. Is the red and black combo a little much?

The red is a cherry red, from this website. http://digitalsynopsis.com/design/color-thesaurus-correct-names-of-shades/