Try findation.com to compare foundation colours; ideally enter a couple of foundation brands and shades that you know suit you, it'll then offer suggestions for other shades and brands that should suit you. Mind you when I tried this just now I had to wade through a long list before I got to a Josie Maran suggestion, so then I tried it the opposite way- add the JM matchmaker foundation (the shade you think would be right for you) at the outset along with other ones you know suit and see if the results look right (works for me because I've tried so many foundations over the years). If your current favourite shows up in your results you've probably picked the right JM shade for you
I've tried the Fair/Light and the Light/Medium but the Fair/Light looks better on me - it evens out my skintone without adding any yellow tones, but doesn't make me look deathly pale once I've added the rest of my face. My 19 year old daughter loves JM products but didn't like the Matchmaker foundation, although she does prefer more coverage. I suggested adding a second layer all over or just for areas that need more coverage but she'd rather use a thicker foundation at the outset. As I've got older I've stopped trying to cover dark circles and every slight freckle (age spot) because it was drawing more attention to the flaws rather than disguising them, and I'd end up looking worse!
Light/Medium is nearly limited stock at 9am!
PS the shades are v forgiving: both Craig and Kathy are wearing the darkest shade from the TSV on today's morning show!