Please send help

So I was recently reading a historical manhwa (straight). I can't remember the details but as far as I know... She was a genius engineer or something, then she created a device that can alter the color of ones eyes. She desperately wanted to fit in the family by changing her eye color (?). But she regressed and she gave that eye changing color to the Crown Prince/ ML ,(?) she has blonde hair and she has a new cousin that turned everything upside down.

Thanks in advance!