Identification of the 2¢ large banknote
Step 2 - Which color?
Why did the color change?
The color change from the 1870 2¢ #135/#146 (Red Brown) to #157 (Brown) to distinguish between the printings of the National Bank Company’s and the Continental Bank Company’s printings. The Continental Bank Note Co. added a secret mark but it is so small as to be unidentifiable.