1851-1857 Franklin 1c Color

I've noticed the 1851 Franklin (Scott #5-9, 18-24) series has at least two distinct colors: a darker blue vs a lighter (almost pastel) blue. Sorry I don't have examples to throw up here right this minute.

My question is if anyone knows a pattern to the color? For example, if you see a light blue, you know it came from Plates xyz.

I don't think it's possible to positively identify printing plate by color. Plate 1 early state colors alone range from very pale blue to dark blue. Neinken states that plate 1 early can be classified as 3 distinct colors; pale blue, blue and dark blue with the great majority of printings found in the pale blue color. Plate 2 stamps range in color from a rather light pale blue tint to a very deep blue shade.

Thanks, Stallzer. So it sounds like similar shades vary with many of the plates, which I find interesting. I would have guessed that whatever change in ingredients that cause the ink color to vary would be more consistent over time (i.e. later plates are darker than the early plates, or vice versa). If the same varities occur within the printing window for multiple plates, that seems to suggest that only one blue was intended and any varying shades are purely coincidental.

For the One-Cent 1851-57 plates color can only be used as a general guideline. I always found it interesting that color shades have been so important in classifying the Three-Cent 1851-57, while for the One-Cent color has been almost an afterthought.

Also not all 1¢ stamps can be plated and there are still many positions on some of the plates with very little data.

IMO, the only really distinctive color is the pale blue found on Plate 1E. Once you have learned it you will know when you see it.

Stallzer, A lot of work has been done on identifying plating marks on all plates since the Nienken book was published. The only real mysteries left are some positions on Plate 3 and most of Plate 11.

On second thought, quite a few Plate 12 stamps can be identified by a lighter blue color.