Peter's suggestion of using Pinto Green is correct, I believe the color he is refering to is "Light Green Gold Metalic", which is Ford color code 4Z in 1975, but keep in mind that not only were there several shades of this green over the years from Raleigh, you must also keep in mind that the paint you are trying to match may also be faded. I usually try to match the paint found on the steer tube, where it's not likely to have faded, especially if you are looking at a total repaint. When using off the shelf touch up paint, you will also find that different brands, and often different batches of the same color may vary slightly. Also, the color which is beneath the new paint can affect the final color. If the paint looks dark, use a lighter primer, or even a silver base coat. I ran into this trying to match Raleigh Coffee brown on a Sports model, Plasticote 8104 is a real close match, but if sprayed on top of an existing color, it comes up too dark, if I use a silver base coat, I get an exact match. You may have to experiment with different combinations to get the color you need. Keep in mind that most paint shops or body shop suppliers offer color matching, if you bring them a good sample, they can usually mix you a perfect match, which is helpful if your trying to match faded paint. Some can also put the custom mixed paint in an aerosol type can for those of you who don't want to be bothered with a spray gun. Be sure to tell who ever is mixing the paint what type of paint or results you want, the simplest is a single step paint, with no clear or base coat other than a primer. If you are doing an entire bike, that part really won't matter, but lacquer based paints are much more forgiving, and tend to give a more factory finish after being hand rubbed, especially on the older British bikes. The newer Acrylic Enamels are often too glossy or 'plastic' looking to achieve the right look on an old bike. Also, you may have trouble finding these colors at the local auto parts store, most of the touch up paint that they stock only goes back about 15 to 20 years at best, these colors are not in demand in touch up cans , so they no longer get stocked, many are obsolete, leaving no other option but to have it custom mixed.
Don't feel bad about using a "Pinto" color, Ford used this color or several variations of it on everything from Pinto's, to Maveric's, to F-Series trucks.
Here are a few links I have found online to some paint information for Ford:
http://www.lovefords.org/tech/Vin/paint/default.htm (Ford Color Chart info)
http://www.lovefords.org/tech/Vin/paint/ford/75_fandchips.htm (Paint chip chart for 1975 Ford
http://www.lovefords.org/tech/Vin/paint/ford/75_f.htm (PPG Color code - Name - OEM Code chart)
http://www.automotivetouchup.com/spray_paint.asp (online paint source, offers paint by code # for touch up)
Hope this helps!