My boss made me redo a whole client slide deck over one color choice

I had this dark blue text on a navy background, looked fine to me on my monitor. Boss ran it through a contrast checker tool and it failed big time, like a 2.5:1 ratio. I switched the text to a light gray and got it over 7:1. The difference was crazy, you could actually read it from across the room. I spent 3 hours redoing all the slides because I didn't check first. Has anyone else had a client or boss catch a major fail you just missed?