01 Luminous Radiance is a light pink-toned beige.
02 Luminous Ivory is a light yellow-toned beige.
03 Light Peach is a warm orange-y tan shade.
If I'm not wrong, I've been told that pink counteracts brown eyebags, and yellow counteracts blue/purple undereye circles. I'm sure there are all sorts of theories, contradictory and otherwise, going on out there, but I believe that's the general rule of thumb if you're absolutely clueless and have no idea where to start. Of course it's not going to work 100% for everyone, but it's just a starting point, like all other makeup 'rules'.
To be fair, although I keep hearing complaints about how sheer Touche Eclat is, I didn't feel that they were really that sheer when swatching, although they definitely weren't as pigmented as some of the more pigmented products on the market. I guess if radiance is a main concern, and your undereye circles aren't too dark, and you don't mind the fiddly click-pen dispenser, this would be ideal.