French Equatorial Africa 1947 Postage Due Stamps

I have Sc J12 and & J14 that show either shading of the entire design or double impression. The 10c J12 shows a light red shading (double impression???) that matches the entire design. The 50c J14 shows a green shading or double impression that also matches the entire design but not as neatly as the 10c. Scott also calls out the J14 as greenish blue. Mine is black with the greenish color underneath. Can anyone shed some light on this?

Ono of the best close ups of a stamp I've seen in this forum.
Your stamp is greenish blue.
Your pic is not picking up the colors.
Colors enhanced below from your excellent pic.

Yvert, Maury and Gibbons all list the 50c as black. Perhaps someone at Scott is colour-blind.

I used a USB microscope to capture the image. Still not sure about the color. Laid a color gage over the stamp and looked at it on the scope. Still appears black. Actually deeper black than the gage.

Other on-line sources list it as black also.

https://www.wikitimbres.fr/co/timbr...le-francaise
A microscope cannot distinguish the light emission from the pigment.
Your digital camera can;but you have to look for it.
Another reason that in the catalogs this stamp is indicated as black is that from the day the stamp was released ; the official records listed it as black.That does not mean that during the actual printing the real black ink used ;but a very dark blue green (almost black).

Thanks all