as we've seen in culture after culture before, a thriving middle-class nurses the arts and 18th century japan was no different. with the edo period, the long isolationist era, peace and prosperity reigned across the land.
kabuki theater, poetry -- humorous and serious, the novel, the visual arts -- prints, paintings, and illustrated books -- and the sexual ones -- the courtesan districts, for example, prospered. and as a sort of visual chronicle of these growing realms, ukiyo-e -- images of this floating, ephemeral, world, was born as well.
what began as painting quickly turned to (at first) black-ink, occasionally hand- colored, prints, due to their ease of reproduction and the money there-by to be made. not surprisingly, shunga was among the first genre to achieve major popularity. (it would be the waves of censorship that would bring back the landscape.)
the full-color print, however, was soon to follow, and it was primarily used in the shunga; it was a natural hit, given all the newly- found free time. here's where we get to that debate again, though.
many, including the artist himself, attribute its invention to haranobu suzuki, late in the 18th century. but there is debate. some credit hu cheng yen, in china in the 17th century. "This was the medium the amateurs of erotica had been looking for." 1
some, though, credit the jesuits for introducing this to the chinese (if they had only known!).
some point to the witch paintings of hans baldung grien, a german artist in the early 16th century, but since there is very little information about his full-color process, i believe it was the tool known as the pen which provided the reds, yellows and blues.
in any case, does it matter? it would not be the first time technology travelled east while philosophy/ design travelled east, nor, as you know, would it be the last. but as i said, haranobu said he was the man. "The inventor of the color printing was Suzuki Harunobu (1725-1770). Harunobu had begun with the printing from the three or four woodblocks, gradually enlarging the number of the blocks to seven or nine." 2
(note how the prints are still somewhat 'primitive' to what our eyes are used to, as does the color.)
during the 17th and 18th centuries, as prosperity flourished, more and more dutch books (except those on religion) were allowed into japan. books of botany and anatomy, history and works by german copper-plate artists. we can see their tell-tale footprints everywhere. just as we can see the simplification of line, a shift in perspective, and a new awareness of the moment in the west in all the arts.