Nissanman recently scored a color chart for 1964 Datsun/Nissan and shared it with us. You can view it by clicking on the this link 1964 Colour Chart
Below paint codes are compliments of JH Bahn and Dupont with major editing.
Manufacturer paint code location:
None shown on cars thru '66; on firewall for '67 and later models. Clicking on a thumbnail image just brings up a small example. Your video card and monitor will have a direct affect on the colors viewed. **mark indicates roadster stock colors. 664 Spanish Red and 665 Yellow seem to be missing in action.