It's interesting that I can find things online that refere to the Yosemite Green like this link to a diecast truck in that color:

http://www.everstoystore.com/finditem.cfm?itemid=8811

That helped me find another source that lists Yosemite Green as a 1940 Ford Truck Color. It has a DITZCO paint code of QDE-1512 and IM-2208.

The chip is not too clear, but here is the link to the page and website I found it on:

http://www.tcpglobal.com/aclchip.asp...Truck-pg01.jpg

and the actual chip is on this page:

http://www.tcpglobal.com/aclchip.asp...Truck-pg03.jpg

And I typed it into their order form
and got:

Selection Summary
FordTruck - 1940 Exact Color : Yosemite Green
Chip Formula #: QDE-1512
Mfg Paint Code: IM-2208

Item No Description Your Price Qty Uom
RSP AE-B-GL AE-ACRYLIC ENAMEL "B" COLOR RESTORATION SHOP PAINT $104.95 GL
RSP AE-B-QT AE-ACRYLIC ENAMEL "B" COLOR RESTORATION SHOP PAINT $34.95 QT

I'll let you take a look seems like these guys can mix it for you. Odd it didn't come up the last time I searched!