So for reference, I am:
C4/NC40 for MAC Studio Fix Powder
NC32/35 for MAC Studio Tech (NC32 being a tiny bit light on me)
NC35/37 in Studio Sculpt
and I am Natural Beige in both Maybelline and Neutrogena.
That being said, I never ever trust MUAs any more with color matching. I always get matched as 153/170/173 in MUFE HD and NC40/42/43/C6 in MAC and I look bright orange. Plus the color doesn't match my neck and chest one bit since they are both already significantly lighter than my face as is. I have to do a LOT of research before going out and purchasing foundation colors and look at a lot of foundation matching charts online before making a decision in person.
For MUFE HD, I have tried 123, 125, 127, 128, 140, 153, 155, 170, 173. 170 and 173 are not even close to my color and I think they would be a better match for people who are NC43-45 or even darker. 153 was bright orange and probably a good match for someone NC42/43. 128 and 155 were very similar, I would put 128 at about NC40/42 and 155 at NC42 with a strong beige/neutral undertone. 127 and 140 were nearly identical but 127 was slightly more yellow and pale and 140 was slightly more peachy. 125 really brightens up my face but it still wasn't the perfect match. Then came 123, ah 123! It says it's for light skin with an olive undertone and I think it is an amazing color for anyone who finds 127 too light and 153 too dark, it is the PERFECT in between. I would recommend it for anyone who has yellow, beige or especially olive undertones, strong warm coloring (Indians, Asians, etc), and people who have light to medium complexions. It is the perfect color for anyone who ranges between NC32-NC37. I think some NC40's can get away with it too if they find 153 too dark like I did.
Hope that helps everyone!