Thank you! I'm going to give the 6.5 a shot. Illamasqua recommended Sb5 but I'm not too sure that will work.I wear B20 in Chanel vitalumiere and use the Illamasqua skin base in 6.5. The .5 numbers seem to have the olive/yellow undertones so right now since I'm a little more tan than in the winter I was hoping to play with one of the higher .5 numbers like 7.5 or 8.5 since I'm definitely olive toned and just look so odd in pink or even peach undertones foundations *glares at Guerlain sample* ! I haven't tried the higher numbers on me but my best guess (I admit I'm not a makeup professional ) is that B30 would have to be up in higher numbers like 9, 10, or 11 and then with a .5 if you need the olive/yellow undertone. I kinda rambled but I hope this was a little helpful. Good luck with your hunt! Do you have a location nearby where you can play with testers?