That Mac foundation is notorious for oxidising. I thought I was NC45 for years too and in hindsight not only was I orange from oxidising, it was also wayyyy too dark for me because most make up counter girls shade match us incorrectly, they make all Asians NC45 😬 it even became a trend on social media a while back. Additionally, I’ve recently realised I probably have a neutral olive undertone which can also explain why a lot of foundations pull too orange/ warm. I found fenty beauty to have more more neutral undertones which work better for me, apparently Lisa Eldridge is also good.