The "honest that he couldn't tell for sure" part is doing a lot of work here, because a timing belt on a 30 year old car isn't something you guess at, it's something you replace on a schedule or when you can see cracks and wear. A guy running a pawn shop shouldn't be the last word on a 60k service item, and telling you to skip it to save $600 when the downside is a $275 tow plus a possible motor is a bad trade every time. Maybe he meant well and maybe he just didn't want the job, but either way you got bad advice dressed up as honesty. On a '92 Miata the belt is cheap insurance, and the smart move is to just do it if there's no record of it being done. I'd take it to a shop that actually knows Miatas next time and not let a pawn guy talk me out of maintenance.

What if you frame it as the box color being a bad match for her hair, not her being dumb for buying it? Like "this shade fights the warmth in your ends, that's where the green comes from" and then show her a swatch of what you'd use instead. She hears it as you protecting her hair and her money, not scolding her. Then the free fix talk never comes up because she feels like you two picked the color together.