Seal Color On 1934-A 20$ Notes

There is no exact standard for determining what is a "Light Green Seal", other than it is generally accepted that FRNs of the 1928C series are in fact the original "true" (lime) LGS notes. Subsequent series were often issued in both dark and light colors, and the accepted serial number ranges for each are readily available for each series and denomination.

The problem (which you allude to) is that "light" and "dark" are arbitrary terms, and in fact the colors vary from series to series. So, for example, the accepted "light" version in one series might look fairly close to a "dark" version in a subsequent series, and in fact might bear no resemblance at all to the original "lime" color.

Complicated subject, but I can state that the true yellowish lime color is quite appealing. You know it when you see it, and it really does not exist in many series despite the light/dark serial number categories.

Schwartz and Lindquist (Standard Guide to US Small Size Paper Money) state simply that "In the end is is up to those involved in the transaction to determine if the buyer is willing to pay the Light Green Seal premium attached to the designation".

Our member "amrys" is the last word on this subject, and perhaps he would chip in.