I hastily bought MAC Studio Fix Liquid in NC50. (I live in South Korea and it is rare to find any foundation for darker tones. It looked okay in the mall, but it was probably a bit too dark then, and it was the only dark color they had.) I am thinking I can buy a lighter shade online and mix the two? But I don't know which to buy. Also it is too red for me. I'm actually more yellow/gold. What should I buy to mix with it? Thanks.