Hi Jean, thanks for your question. The general answer is that you can let your personality shine, whatever your outfit looks like. I love color too; as I write this, my top is bright orange, bright pink, and black.
You have to remember that engineering is no different from law, from medicine, from accounting, etc. – to be taken seriously, we need to dress professionally, in and out of the office. Now this certainly allows for dresses, skirts, colorful outfits, jewelry, high heels, etc. Just not all at once, no 5-inch heels, nothing low-cut, no mini-skirts, and no glitter. If your daughter still likes wearing glitter after college, the time and place is when she goes out at night or on the weekends, same as it would be if she worked in another job.
I’d hope your daughter wouldn’t shun a rewarding, potentially lucrative profession just because “wearing glitter in the office is frowned upon” – but that’s for her to decide. Wishing her luck in her future endeavors!