The background color of a manga paper when scanned online is changed by the scanlators to white (#FFFFFF).
However, this is not the background color in an actual manga book. the color in the manga book looks little grayer in the paper.
What I am trying to do, is to publish a manga online with the same real background color.
The color varies widely based on multiple factors:
Therefore, I can't 100% give you a color estimate (it could be anything from very light yellowish-gray to very dark gray).
As for paper types. There are also several types of paper that could be used for printing manga:
There are probably a whole lot more, but that's the prominent two I know of.
Magazines like Jump tend to use 85% recycled paper for their pages.
These tend to be cheaper than ones collected in published volumes. The color of these pages may very by publisher, but Jump tends to use green, yellow, and pink for their pages. The pages are cheaply made in order to keep costs down and because it's expected to have them be thrown away afterwards. Thus they are not suitable for long-term storage as they are fragile, vulnerable to deterioration from moisture and light.
As mentioned before the print paper used for magazine is mostly recycled. Usually when creating recycled paper, there is a process called de-inking is used. This involves bleaching to remove the ink and and dark spots or other imperfections like dirt. However as more recycled paper is involved in the process, the process becomes harder and more expensive. In order to save costs, coloring is used instead to mask the dark spots and other imperfections.
If you look at the sides of magazine you'll notice the pages are colored differently. The idea from the publishers is to vary the colors and keep things interesting and sometimes also separate different genres from one another.
You can't tell in scans because they artificially adjust the levels to clean them up, so often times the page colors go in noticed.
Solution: I also had this question, but I ended up having to make color combinations, print them out, and compare them to physical copies of manga I had. The closest color combination I was able to make was: (R, G, B) = (238, 230, 201).
ik I'm 3 years too late but I was trying to do the same thing for a project, I did this in Figma using E4DAC9 as the color, and used this tool to add grain: https://www.figma.com/community/plugin/1138854718618193875/noise-texture
the borders look drawn by hand because I used a paint tool with a brush that looks like a lead pencil and I just made different patches and cropped out a part that I liked out of the patch and saved it as a PNG. Then set that as the image for the border (stroke setting in Figma) and set the stroke to the tile setting at 100%.
